Answer:
a) We can not estimate the probability.
b) Zero probability.
c) There is a probability between 95% and 99% that they have between 475 and 525 customers on a given day.
Step-by-step explanation:
a) We can not said nothing because we only know the average of customers per day. We need to know the probability distribution of the amount of customers per day to answer this question.
b) Now that we know that the variance is 100, although we do not know the exact distribution of the values, we can use the empirical rules to estimate the probability of having at least 700 customers on a given day.
If the variance is 100, the standard deviation is √100=10.
Applying the empirical rule (68-95-99.7 rule), we know that there is probability 0.15% of having at least 500+3*10=530 customers per day (more than 3 deviations from the mean).
Then, we can conclude that the probability of having at least 700 customers per day is zero.
c) To estimate this probability, we have to calculate how many deviations from the mean this values represent:
[tex]\Delta_1=475-500=-25=2.5\sigma\\\\\Delta_2=525-500=25=2.5\sigma[/tex]
We have an interval that have a width of ±2.5 deviations from the mean.
For 2 deviations from the mean, it is expected to have 95% of the data.
For 3 deviations from the mean, it is expected to have 99.7% of the data.
Then, for the interval 475 to 525, we can estimate a probability between 95% and 99%.
Barron's reported that the average number of weeks an individual is unemployed is 18.5 weeks. Assume that for the population of all unemployed individuals the population mean length of unemployment is 18.5 weeks and that the population standard deviation is 6 weeks. Suppose you would like to select a sample of 55 unemployed individuals for a follow-up study.
A) show the sampling distribution of x, the sample mean average for a sample of 50 unemployment individuals.B) What is the probability that a simple random sample of 50 unemployment individuals will provide a sample mean within one week of the population mean?C) What is the probability that a simple random sample of 50 unemployed individuals will provide a sample mean within a half week of the population mean?
Answer:
A) The sampling distribution for a sample size n=50 has a mean of 18.5 weeks and a standard deviation of 0.849.
B) P = 0.7616
C) P = 0.4441
Step-by-step explanation:
We assume that for the population of all unemployed individuals the population mean length of unemployment is 18.5 weeks and that the population standard deviation is 6 weeks.
A) We take a sample of size n=50.
The mean of the sampling distribution is equal to the population mean:
[tex]\mu_s=\mu=18.5[/tex]
The standard deviation of the sampling distribution is:
[tex]\sigma_s=\dfrac{\sigma}{\sqrt{n}}=\dfrac{6}{\sqrt{50}}=0.849[/tex]
B) We have to calculate the probability that the sampling distribution gives a value between one week from the mean. That is between 17.5 and 19.5 weeks.
We can calculate this with the z-scores:
[tex]z_1=\dfrac{X_1-\mu}{\sigma/\sqrt{n}}=\dfrac{17.5-18.5}{6/\sqrt{50}}=\dfrac{-1}{0.8485}=-1.179\\\\\\z_2=\dfrac{X_2-\mu}{\sigma/\sqrt{n}}=\dfrac{19.5-18.5}{6/\sqrt{50}}=\dfrac{1}{0.8485}=1.179[/tex]
The probability it then:
[tex]P(|X_s-\mu_s|<1)=P(|z|<1.179)=0.7616[/tex]
C) For half a week (between 18 and 19 weeks), we recalculate the z-scores and the probabilities:
[tex]z=\dfrac{X-\mu}{\sigma/\sqrt{n}}=\dfrac{18-18.5}{6/\sqrt{50}}=\dfrac{-0.5}{0.8485}=-0.589[/tex]
[tex]P(|X_s-\mu_s|<0.5)=P(|z|<0.589)=0.4441[/tex]
Help, please. I dont really understand
Answer:
We can eliminate the second and third options because marking something up doesn't result in a number less than the original. Since we are told to select 3 options and there are 3 answer choices left we select the first, fourth, and fifth statements.
Which of the following sequences is arithmetic? A 3, 9, 15, 21, 27, . . . B 3, 9, 17, 27, 39, . . . C 3, 9, 27, 81, 243, . . .
Answer:
A) 3, 9, 15, 21, 27, . . .
Step-by-step explanation:
EDGE 2020
Answer:
The second answer is 6.
Step-by-step explanation:
D=6
Which of the following are solutions to the quadratic equation? Check all that apply x^2 + 12x + 36 = 7
Answer:
x = -6 + [tex]\sqrt{7}[/tex], x = -6 - [tex]\sqrt{7}[/tex]
Step-by-step explanation:
(x + 6)² = 7
x + 6 = + or - [tex]\sqrt{7}[/tex]
x = -6 + [tex]\sqrt{7}[/tex], x = -6 - [tex]\sqrt{7}[/tex]
The solution of the quadratic equation is x = -6 +√7, x = -6 - √7.
What is a quadratic equation?A quadratic equation is a polynomial with a degree of 2 or the maximum power of the variable is 2 in quadratic equations. It has two solutions as its maximum power is 2.
Completing the square entails writing a quadratic in the form of a squared bracket and, if necessary, adding a constant. Finding the maximum or minimum value of the function and when it occurs is one application of completing the square.
Given that the quadratic equation is x² + 12x + 36 = 7.
(x + 6)² = 7
x + 6 = ±√7
x = -6 + √7 , x = -6 - √7
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Solve for y
A)16
B)18
C)22
D) 30
Omg help me I need help, please help me I’m so nice and funny, I can make u laugh, help me freaks I’m big baller
Answer:
30
Step-by-step explanation:
It is an equalateral triangle
Describe the steps you would use to solve the
following inequality
2x - 3
Answer: No answer
Step-by-step explanation:
Not an inequality, inequalities are of the form 2x - 3 > something.
If it's 2x - 3 > 0 for example, then add both sides by 3 to get 2x > 3, then div by 2 to get x > 3/2.
Hope that helped,
-sirswagger21
SOMEONE PLEASE HELP ME ASAP PLEASE!!!
Answer:
105.12 ft^2
Step-by-step explanation:
Area of a rectangle: bh
In this case 8*10.... so area of the rectangle is 80
Area of a circle: pir^2
Half it for a semicircle.
so 1/2 pi r^2
radius is 4 cuz its half of 8.
so 1/2(3.14)(4^2)=(0.5)(3.14)(16)=25.12
Now add up 80+25.12
Total is 105.12
Hope I helped :)
The accompanying data represent the total travel tax (in dollars) for a 3-day business trip in 8 randomly selected cities A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot indicates there are no outliers. Complete parts through below.
68.87 78.25 70.44 84.67 79.79 86.33 100.24 98.26
Click the icon to view the table of critical t-values.
a. Determine a point estimate for the population mean travel tax A point estimate for the population mean travel tax is $ 83.36. (Round to two decimal places as needed.)
b. Construct and interpret a 95% confidence interval for the mean tax paid for a three-day business trip.
Select the correct choice below and fill in the answer boxes to complete your choice. (Round to two decimal places as needed.)
A. The lower bound is $ and the upper bound is $. One can be % confident that all cities have a travel tax between these values.
B. The lower bound is $ and the upper bound is $ The travel tax is between these values for % of all cities.
C. The lower bound is $ and the upper bound is $ There is a % probability that the mean travel tax for all cities is between these values.
D. The lower bound is $ and the upper bound is One can be [95]% confident that the mean travel tax for all cities is between these values.
c. What would you recommend to a researcher who wants to increase the precision of the interval, but does not have access to additional data?
A. The researcher could decrease the level of confidence.
B. The researcher could decrease the sample standard deviation.
C. The researcher could increase the level of confidence.
D. The researcher could increase the sample mean
Answer:
Step-by-step explanation:
Given that:
68.87, 78.25, 70.44, 84.67, 79.79, 86.33, 100.24, 98.26
we calculate sample mean and standard deviation from given data
Sample Mean
[tex]\bar x = \frac{\sum (x)}{n} =\frac{666.85}{8} \\\\=83.35625[/tex]
Sample Variance
[tex]s^2= \frac{\sum (x- \bar x )^2}{n-1} \\\\=\frac{933.224787}{7} =133.317827[/tex]
sample standard deviation
[tex]s=\sqrt{s^2} \\=\sqrt{133.317827} \\ =11.546334[/tex]
95% CI for [tex]\mu[/tex] using t - dist
Sample mean = 83.35625
Sample standard deviation = 11.546334
Sample size = n = 8
Significance level = α = 1 - 0.95 = 0.05
Degrees of freedom for t - distribution
d-f = n - 1 = 7
Critical value
[tex]t_{\alpha 12, df}= t_{0.025, df=7}=2.365[/tex] ( from t - table , two tails, d.f =7)
Margin of Error
[tex]E = t_{\alpha 12, df}\times \frac{s_x}{\sqrt{n} } \\\\=2.365 \times \frac{11.546334}{\sqrt{8} } \\\\=2.365 \times 4.082246\\\\E=9.654512[/tex]
Limits of 95% Confidence Interval are given by:
Lower limit
[tex]\bar x - E = 83.35625-9.654512\\\\=73.701738\approx 73.702[/tex]
Upper Limit
[tex]= \bar x + E\\=83.35625+ 9.654512\\=93.010762 \approx 93.011[/tex]
95% Confidence interval is
[tex]\bar x \pm E = 83.35625 \pm 9.654512\\\\=(73.701738,93.010762)[/tex]
95% CI using t - dist (73.70 < μ < 93.01)
D. The lower bound is $ and the upper bound is One can be [95]% confident that the mean travel tax for all cities is between these values.
c.What would you recommend to a researcher who wants to increase the precision of the interval, but does not have access to additional data?
A. The researcher could decrease the level of confidence.
Find the length of Line segment A C . Use that length to find the length of Line segment C D . Triangle A B C is shown. A perpendicular bisector is drawn from point A to point C on side B D. Angle A B C is 30 degrees and angle A D C is 25 degrees. The length of A B is 10 centimeters. What is the length of Line segment C D? Round to the nearest tenth. 2.3 cm 4.0 cm 10.7 cm 18.6 cm
Answer:
10.7 CM
Step-by-step explanation:
Correct on Edge 2020
Answer:
answer is C 10.7 cm
Step-by-step explanation:
got it right on edg 2020-2021
A survey taken in a large statistics class contained the question: "What's the fastest you have driven a car (in miles per hour)?" The five-number summary for the 87 males surveyed is: min = 55, Q1 = 95, Median = 110, Q3 = 120, Max = 155 Should the largest observation in this data set be classified as an outlier? No Yes
Answer:
NO
Step-by-step explanation:
To find out which observation to classify as an outlier, whether the largest or not, a very good approach or way to do this is to apply the 1.5(IQR) rule.
According to the rule, for finding the largest observation in the data that can be classified as an outlier, we would use the formula = Q3 + 1.5(IQR).
Q3 = 120
IQR = Q3 - Q1 = 120 - 95 = 25
Lets's plug these values into Q3 + 1.5(IQR)
We have,
120 + 1.5(25)
= 157.5
Since our max in the observation is given as 155, the largest observation in the data set cannot be set as an outlier because 157.5 which we got from our calculation is higher than the max value we have in the data set.
Our answer is NO.
However, the smallest observation should be set as outlier because:
Q1 - 1.5(IQR) = 95 - (1.5*25) = 57.5, which gives us an outlier that falls within our data range.
A sample of 899 Americans provides enough evidence to conclude that marketing campaign was effective. Provide a statement that should be put out by the marketing department. A. There is not sufficient evidence to conclude that the mean consumption of popcorn has risen. B. There is sufficient evidence to conclude that the mean consumption of popcorn has risen. C. There is sufficient evidence to conclude that the mean consumption of popcorn has stayed the same. D. There is not sufficient evidence to conclude that the mean consumption of popcorn has stayed the same.
Answer:
The correct answer to the following question will be Option A.
Step-by-step explanation:
Marketing Analyst seems to be responsible for information and evaluation that directs its marketing team and directs its marketing approach by defining the target clients as well as the competitiveness of the product.A survey of 899 American citizens requires appropriate evidence to demonstrate that perhaps the marketing strategy is working even though there was not considerable evidence to suggest that even the total demand for popcorn had increased.Other given choices are not related to the given circumstances. So that option A seems to be the appropriate choice.
Two number cubes are rolled for two separate events:
Event A is the event that the sum of numbers on both cubes is less than 10.
Event B is the event that the sum of numbers on both cubes is a multiple of 3.
Complete the conditional probability formula for event B given that event A occurs first by writing A and B in the blanks:
P ( _a0 | _a1) = P ( _a2 ∩ _ a3)
___________
P ( _a4)
Answer: [tex]\bold{P(B|A)=\dfrac{P(B\cap A)}{P(A)}=\dfrac{11}{30}}[/tex]
Step-by-step explanation:
The probability of Event B given Event A = the intersection of Event A and B divided by the probability of Event A. (see below for the symbols)
[tex]P(B|A)=\dfrac{P(B\cap A)}{P(A)}[/tex]
P(A) = (1, 6), (1, 5), (1, 4), (1, 3), (1, 2), (1, 1)
(2, 6), (2, 5), (2, 4), (2, 3), (2, 2), (2, 1)
(3, 6), (3, 5), (3, 4), (3, 3), (3, 2), (3, 1)
(4, 5), (4, 4), (4, 3), (4, 2), (4, 1)
(5, 4), (5, 3), (5, 2), (5, 1)
(6, 3), (6, 2), (6, 1)
= 30
P(B) = (1, 2), (2, 1) sum = 3
(1, 5), (2, 4), (3, 3), (4, 2), (5, 1) sum = 6
(3, 6), (4, 5), (5, 4), (5, 4), (6, 3) sum = 9
(6, 6) sum = 12
= 12
P(A ∩ B) = (1, 2), (2, 1)
(1, 5), (2, 4), (3, 3), (4, 2), (5, 1)
(3, 6), (4, 5), (5, 4), (5, 4), (6, 3)
= 11
how many real solutions does the equation x2 − 9 = 0 have?
Answer:
Zero
Step-by-step explanation:
Because when you replace x with a number and solve it it doesn't have the same answer as x2 − 9 = 0.
I hope this helped. I am sorry if you get this wrong.
In the past, 35% of the students at ABC University were in the Business College, 35% of the students were in the Liberal Arts College, and 30% of the students were in the Education College. To see whether or not the proportions have changed, a sample of 300 students from the university was taken. Ninety of the sample students are in the Business College, 120 are in the Liberal Arts College, and 90 are in the Education College. This problem is an example of a a. Marascuilo procedure. b. multinomial population. c. z test for proportions. d. test for independence.
Answer:
The correct answer will be Option B (multinomial population).
Step-by-step explanation:
The population is considered as multinomial whether its information is prescriptive or corresponds to the set of discreet non-overlapping groups. The hypothesis again for fitness test besides multinomial distribution is that even though the approximately normal f I seem to be equivalent to the required number e I across each segment.Here, because we have been testing whether the sampling data matches the hypothesized proportions as mentioned, this is indeed a multinomial population issue (because there have been more least two generations).Other given options are not connected to the given situation. So that Option B seems to be the perfect solution.
In order to get toys from under the couch, Mom lifted up the couch to an angle of 31 degrees. The kids still could not reach the toys. Then, she lifted it up another 15 degrees, and the kids pulled out a bouncy ball, a foam dart, three rubber bands, and a Lego. What was the measure of the total angle Mom lifted the couch?
Answer:
46 degrees
Step-by-step explanation:
Add 31 + 15 together to find the total angle
31 + 15 = 46
= 46 degrees
Answer:
That is 46°.
Step-by-step explanation:
31 + 15 = 46
So, 46°.
Define a function sinc(x) (pronounced "sink of x") by: text(sinc)(x)={(sin(x)/x text(if)\ x != 0, 1 text(if)\ x = 0.) (This function is used frequently in electrical engineering and signal processing.) Use this list of Basic Taylor Series to find the Taylor Series for f(x) = sinc(x) based at 0. Give your answer using summation notation and give the largest open interval on which the series converges. (If you need to enter [infinity] , use the [infinity] button in CalcPad or type "infinity" in all lower-case.)
Answer:
Step-by-step explanation:
To find the Taylor series of sinc(x) we will use the taylor series of sin(x). We have that
[tex]\sin(x) = \sum_{n=0}^{\infty}\frac{(-1)^n x^{2n+1}}{(2n+1)!}[/tex]
which is the taylor series expansion based at 0. Then for [tex]x\neq 0[/tex], by dividing both sidex by x, we have that
[tex]\text{sinc}(x) = \frac{\sin(x)}{x}= \sum_{n=0}^{\infty}\frac{(-1)^n x^{2n}}{(2n+1)!}[/tex]
which is the taylor series expansion for the sinc function. Since the series of sine converges for every value of x. Then the taylor series of sinc converges for every value of x, but 0.
How to find a vertical asymptote
Answer:
Step-by-step explanation:
Generally's rational functions that have vertical asymptotes, even trig functions (which, like the tangent function, are often rational).
If the given function is the ratio of two functions, polynomial or otherwise, the graph of the given function has an asymptote at any x value for which the denominator is zero. Example: y = tan x = (sin x) / (cos x) has vertical asysmptotes at π/2, 3π/2, and so on, because the denominator cos x is zero for those angles.
Goodlife charges its members $30 per month for a gym membership. They currently have 75 clients.
Research has shown that for every $2 increase in their membership price they will lose 3 clients. If they want to maximize their revenue, how much should Goodlife charge per membership? What will their maximized revenue be?
Is the function given by f(x)equalsleft brace Start 2 By 2 Matrix 1st Row 1st Column one fourth x plus 1 comma 2nd Column for x less than or equals 4 comma 2nd Row 1st Column 4 x minus 11 comma 2nd Column for x greater than 4 comma EndMatrix continuous at xequals4? Why or why not? Choose the correct answer below. A. The given function is continuous at xequals4 because ModifyingBelow lim With x right arrow 4 f (x )does not exist. B. The given function is not continuous at xequals4 because f(4) does not exist. C. The given function is continuous at xequals4 because the limit is 2. D. The given function is not continuous at xequals4 because ModifyingBelow lim With x right arrow 4 f (x )does not exist.
Answer:
C. The given function is continuous at x=4 because the limit is 2.
Step-by-step explanation:
Given the function:
[tex]f(x)=\left\{\begin{array}{ccc}\frac{1}{4}x+1 &x\leq 4\\4x-11&x>4\end{array}\right[/tex]
We are to determine if the function is continuous at x=4.
For a function to be continuous at some value c in its domain:
f(c) must be defined.[tex]Lim_{x \to c}$ f(x)[/tex] must exist. [tex]f(c)=Lim_{x \to c}$ f(x)[/tex]Now: at x=4
[tex]f(4)=\dfrac{1}{4}*4+1=2[/tex][tex]Lim_{x \to 4}f(x)=2[/tex]Since the two values are the same, we say that f(x) is continuous at x=4.
The correct option is C.
Lester worked 12 hours last week at the grocery store and earned $93.00. If he continues to earn the same hourly pay, how many additional hours must he work to earn another $62.00?
A. 9 hours
B. 10 hours
C. 11 hours
D. 8 hours
Answer:
8 hours
Step-by-step explanation:
We can use a ratio to solve
12 hours x hours
---------- = ------------
93 dollars 62 dollars
Using cross products
12 * 62 = 93x
Divide each side by 93
12*62/93 = 93x/93
8 = x
8 hours
Assume that the probability of a driver getting into an accident is 7.1%, the
average cost of an accident is $14,886.05, and the overhead cost for an
insurance company per insured driver is $110. What should the driver's
insurance premium be?
O A. $1276.27
O B. $1242.93
O C. $1165.49
O D. $1156.43
Answer:
C - $1165.49
Step-by-step explanation:
We have that the probability of a driver getting into an accident = 7.1% i.e. 0.071.
Now, the average cost of an accident = $14,886.05
Then, the expected cost of an accident = $14,886.05 × 0.071 = $1056.91
As, the overhead cost for insurance = $110
Therefore, the driver's insurance premium = $1056.91 + $110 = $1166.91
Since, the closest option to $1166.91 is option C.
Hence, the driver's insurance premium will be $1165.49.
the driver's insurance premium will then be,
⇒ $1166.91
What is mean by Percentage?
A number or ratio that can be expressed as a fraction of 100 or a relative value indicating hundredth part of any quantity is called percentage.
To Calculate the percent of a number , divide the number by whole number and multiply by 100.
Now, The following can be deduced from the question:
Average cost of an accident = $14,886.05
Probability of a driver getting into an accident = 7.1%
= 7.1/100
= 0.071.
Overhead cost for insurance = $110
Therefore, the expected cost of an accident will be calculated as:
= Average cost of an accident × Probability of a driver getting into an accident
= $14,886.05 × 0.071
= $1056.91
Therefore, the driver's insurance premium will then be:
= $1056.91 + $110
= $1166.91
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What is 2 1/2 + 1 1/3
Answer:
[tex]=3\frac{5}{6}[/tex]
Step-by-step explanation:
[tex]2\frac{1}{2}+1\frac{1}{3}\\\mathrm{Add\:whole\:numbers}\:2+1:\quad 3\\\mathrm{Combine\:fractions}\:\frac{1}{2}+\frac{1}{3}:\quad \frac{5}{6}\\=3\frac{5}{6}[/tex]
6th grade math :) ........
Answer:
Step-by-step explanation:
1) d
2) c
1) 3 hearts, 7 other shapes that isn't hearts
2) 2 triangs, 5 circles
Answer:
1) d
2) c
Step-by-step explanation:
looks like i was wrong last time lol, this is right for sure tho, i see what i did wrong, sorry
The cost of producing x soccer balls in thousands of dollars is represented by h(x) = 5x + 6. The revenue is represented by k(x)
= 9x - 2. Which expression represents the profit, (k-h(x), of producing soccer balls?
Answer:
4x - 8
Step-by-step explanation:
k - H(x)
(9x -2) - (5x + 6)
4x -8
Which pair of complex numbers has a real-number product?
Answer:
Step-by-step explanation:
the complex number and its conjugate
Answer:
(1+3i)(1-3i)
Step-by-step explanation:
If P(A)=0.4, P(A and B)=0.2,and P(A or B)=0.5, What is P(B)
Answer:
[tex]\boxed{\ P(B)=0.3 \ }[/tex]
Step-by-step explanation:
Hi,
We know that
P(A or B)=P(A)+P(B)-P(A and B)
so P(B)= P(A or B) - P(A) + P(A and B)
so
P(B) = 0.5 - 0.4 + 0.2 = 0.3
thanks
please very soon I offer the crown !!! + 10 points urgently !!!
Answer:
a. 2 groups of 2 is 4
b. 3 groups of 2 is 6
c. 4 groups of 2 is 8
d. 5 groups of 2 is 10
e. 6 groups of 2 is 12
Answer:
a - 2
b- 3
c- 4 groups of 2 is 8
d- 5 groups of 2 is 10
e- 6 groups of 2 is 12
The probability that a member of a certain class of homeowners with liability and property coverage will file a liability claim is 0.04, and the probability that a member of this class will file a property claim is 0.10. The probability that a member of this class will file a liability claim but not a property claim is 0.01. Calculate the probability that a randomly selected member of this class of homeowners will not file a claim of either type.
Answer:
The probability that a randomly selected member of this class of homeowners will not file a claim of either type is 0.89.
Step-by-step explanation:
Denote the events as follows:
X = liability claim will be filled
Y = property claim will be filled
The information provided is:
P (X) = 0.04
P (Y) = 0.10
P (X ∩ Y') = 0.01
The probability that a randomly selected member of the class of homeowners will not file a claim of either type will be given by:
[tex]P[(X\cup Y)']=1-P(X\cup Y)=1-[P(X)+P(Y)-P(X\cap Y)][/tex]
According to the law of total probability:
[tex]P(B)=P(B\cap A)+P(B\cap A')[/tex]
Use the law of total probability to determine the value of P (X ∩ Y) as follows:
[tex]P(X)=P(X\cap Y)+P(X\cap Y')\\\\P(X\cap Y)=P(X)-P(X\cap Y')\\\\=0.04-0.01\\\\=0.03[/tex]
The value of P (X ∩ Y) is 0.03.
Compute the value of P (X ∪ Y) as follows:
[tex]P[(X\cup Y)']=1-P(X\cup Y)[/tex]
[tex]=1-[P(X)+P(Y)-P(X\cap Y)]\\\\=1-[0.04+0.10-0.03]\\\\=1-0.11\\\\=0.89[/tex]
Thus, the probability that a randomly selected member of this class of homeowners will not file a claim of either type is 0.89.
Suppose that a company's sales were $1,000,000 6 years ago and are $9,000,000 at the end of the 6 years. Find the geometric mean growth rate of sales. (Round your answer to 4 decimal places.)
Answer:
The geometric mean growth rate of sales is 1.4422.
Step-by-step explanation:
We have two sales values, one from 6 years ago and the other from now.
We have to calculate the geometric growth rate of sales.
We have:
[tex]y(-6)=1,000,000\\\\y(0)=9,000,000[/tex]
We can write the relation between these two values as:
[tex]y(0)=y(-6)k^{0-(-6)}\\\\9,000,000=1,000,000k^6\\\\k^6=9\\\\k=9^{1/6}= 1.4422[/tex]
The geometric mean growth rate of sales is 1.4422.
Based on aâ poll, among adults who regret gettingâ tattoos, 18â% say that they were too young when they got their tattoos. Assume that eight adults who regret getting tattoos are randomlyâ selected, and find the indicated probability. Complete partsâ (a) throughâ (d) below.
a. Find the probability that none of the selected adults say that they were too young to get tattoos.
b. Find the probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c. Find the probability that the number of selected adults saying they were too young is 0 or 1.
d. It we randomly select 9 adults. Is 1 a significantly low number who day that they were too young to get tattoos?
Answer:
a) 20.44% probability that none of the selected adults say that they were too young to get tattoos.
b) 35.90% probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c) 56.34% probability that the number of selected adults saying they were too young is 0 or 1.
d) No
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they say they were too young when they got their tattoos, or they don't say that. Each adult is independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
18% say that they were too young when they got their tattoos.
This means that [tex]p = 0.18[/tex]
Eight adults who regret getting tattoos are randomly selected
This means that [tex]n = 8[/tex]
a. Find the probability that none of the selected adults say that they were too young to get tattoos.
This is P(X = 0).
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{8,0}.(0.18)^{0}.(0.82)^{8} = 0.2044[/tex]
20.44% probability that none of the selected adults say that they were too young to get tattoos.
b. Find the probability that exactly one of the selected adults says that he or she was too young to get tattoos.
This is P(X = 1).
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 1) = C_{8,1}.(0.18)^{1}.(0.82)^{7} = 0.3590[/tex]
35.90% probability that exactly one of the selected adults says that he or she was too young to get tattoos.
c. Find the probability that the number of selected adults saying they were too young is 0 or 1.
Either a. or b.
20.44 + 35.90 = 56.34
56.34% probability that the number of selected adults saying they were too young is 0 or 1.
d. It we randomly select 9 adults. Is 1 a significantly low number who day that they were too young to get tattoos?
Now [tex]n = 9[/tex]
It is significantly low if it is more than 2.5 standard deviations below the mean.
The mean is [tex]E(X) = np = 9*0.18 = 1.62[/tex]
The standard deviation is [tex]\sqrt{V(X)} = \sqrt{n*p*(1-p)} = \sqrt{9*0.18*0.82} = 1.15[/tex]
1 > (1.62 - 2.5*1.15)
So the answer is no.
