Fifty random shoppers at an electronics store have been interviewed and 35 of them intend to purchase a newly released smart phone. What probability distribution describes this situation and what are its mean and standard deviation of phone sales if we are concerned about 1071 shoppers that day
Answer:
We use the binomial distribution to describe this situation.
The mean number of phone sales is 749.7 with a standard deviation of 15.
Step-by-step explanation:
For each shopper, there are only two possible outcomes. Either they plan to purchase the newly released smart phone, or they do not. Each customer is independent of other customers. So we use the binomial distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
The standard deviation of the binomial distribution is:
[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]
Fifty random shoppers at an electronics store have been interviewed and 35 of them intend to purchase a newly released smart phone.
This means that [tex]p = \frac{35}{50} = 0.7[/tex]
What are its mean and standard deviation of phone sales if we are concerned about 1071 shoppers that day
1071 shoppers, so [tex]n = 1071[/tex]
Mean
[tex]E(X) = 1071*0.7 = 749.7[/tex]
Standard deviation
[tex]\sqrt{V(X)} = \sqrt{1071*0.7*0.3} = 15[/tex]
The mean number of phone sales is 749.7 with a standard deviation of 15.
please help you will get 10 points and brainliest. and explain your answer.
Answer:
Top prism = 262 in.² Bottom prism = 478 in.²
Step-by-step explanation:
top prism:
front + back: 5 x 3 = 15
sides: 19 x 4 x 2 = 152
bottom: 19 x 5 = 95
15 + 152 + 95 = 262
bottom prism:
front + back: 5 x 6 x 2 = 60
sides: 19 x 6 x 2 = 228
top + bottom: 19 x 5 x 2 = 190
60 + 228 + 190 = 478
A man spend 3/5 of his money and has$ 90 left . how much did he have initially
Answer:
225 I believe because if he has $90 that is 2/5 so add another 90 whitch is 2/5 as well and divide 90 by 2 and to get 45 which all adds up to 225
Please answer this correctly
Answer:
28 and 7
35
Step-by-step explanation:
The area of a triangle is base*height/2, no matter the shape.
So the big one is 8*7/2 = 28 in²
And the little one is 2*7/2 = 7 in²
The total trapezoid therefore has an area of 28+7=35 in²
If a random sample of 53 students was asked for the number of semester hours they are taking this semester. The sample standard deviation was found to be s = 4.7 semester hours. How many more students should be included in the sample to be 99% sure that the sample mean x is within 1 semester hour of the population mean for all students at this college?
Answer:
94 more students should be included in the sample.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.99}{2} = 0.005[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.005 = 0.995[/tex], so [tex]z = 2.575[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
How many students we need to sample to be 99% sure that the sample mean x is within 1 semester hour of the population mean?
We need to survey n students.
n is found when M = 1.
We have that [tex]\sigma = 4.7[/tex]
So
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
[tex]1 = 2.575*\frac{4.7}{\sqrt{n}}[/tex]
[tex]\sqrt{n} = 2.575*4.7[/tex]
[tex](\sqrt{n})^{2} = (2.575*4.7)^{2}[/tex]
[tex]n = 146.47[/tex]
Rounding up
147 students need to be surveyed.
How many more students should be included...?
53 have already been surveyed
147 - 53 = 94
94 more students should be included in the sample.
I need help with solving this
Answer:
49
Step-by-step explanation:
Positive 49 not -49
What is the value of
3/7x0.1/5/21
?
7
А.1/98
B.9/50
С.9/5
D.18/1
Answer:
B
Step-by-step explanation:
[tex]\dfrac{3}{7}\times 0.1 \div \dfrac{5}{21}= \\\\\\\dfrac{3}{7}\times \dfrac{1}{10}\times \dfrac{21}{5}= \\\\\\\dfrac{3\times 1 \times 21}{7 \times 10 \times 5}=\\\\\\\dfrac{63}{350}=\\\\\\\dfrac{9}{50}[/tex]
Therefore, the correct answer is choice B. Hope this helps!
Answer:
The answer to your question is 9/50
The radius of a circle is 2.6 in. Find the circumference
to the nearest tenth.
Answer:
16.
Step-by-step explanation:
since given the radius and the formula of the circumference of a circle is 2pie*r
What’s the correct answer for this question?
Answer:
The last option is the correct choice 33.5
Step-by-step explanation:
[tex]V=\pi r^2\frac{h}{3} \\=\pi 2^2\frac{8}{3} \\=33.51\\=33.5[/tex]
Answer:
D
Step-by-step explanation:
In the attached file
which law would you use to simply the expression 3^10/3^4 quotient power power of a quotient product of powers power of a product
Find the surface area of this triangular prism. Be sure to include the correct unit in your answer.
15 m
12 m
0
9 m
11 m
Thanks for anyone that answers
Evaluate the expression 2x-7 for x = -4
Answer:
-15
Step-by-step explanation:
The solution of expression for x = - 4 is,
⇒ - 15
We have to given that,
An expression is,
⇒ 2x - 7
Now, We can simplify the expression for x = - 4 as,
An expression is,
⇒ 2x - 7
Plug x = - 4;
⇒ 2 × - 4 - 7
⇒ - 8 - 7
⇒ - 15
Thus, The solution of expression for x = - 4 is,
⇒ - 15
Learn more about the equation visit:
brainly.com/question/28871326
#SPJ6
What term should be inserted in
p²-
___+36 to make it a perfect
Square
Answer:
12p
Step-by-step explanation:
the perfect square is form
(p - 6)² = p² - 12p + 36
Answer:
12p
Step-by-step explanation:
p² - ? + 36 = p² - ? + (-6)² = p² -2*6*p + (-6)² = p² - 12p + 36 = (p-6)²
A powerful computer is purchased for $2000, but loses 20% of its value each year. How much will it be worth 4 years from now?
a. Growth or Decay?
b. What is your multiplier?
c. Is $2000 your zero term or first term? term
d. Write the equation. (do not use spaces in your response; example: f(x)=10.2(1.22)^x )
e. Solve
Answer:
(A)Decay
(b)0.8
(c)First Term
(d)[tex]f(t)=2000(0.8)^t[/tex]
(e)$819.20
Step-by-step explanation:
The exponential function for modelling growth or decay is given as:
[tex]A(t)=A_o(1\pm r)^t[/tex],
Where:
Plus indicates growth and minus indicates decay.
[tex]A_o$ is the Initial Value\\r is the growth/decay rate\\t is the time period[/tex]
For a powerful computer that was purchased for $2000, but loses 20% of its value each year.
(a)Since it loses value, it is a decay.
(b)Multiplier
Its value decays by 20%.
Therefore, our multiplier(1-r) =(1-20&)=1-0.2
Multiplier =0.8
(c)$2000 is our First term (or Initial Value [tex]A_o[/tex])
(d)The function for this problem is therefore:
[tex]f(t)=f_o(1- r)^t\\f(t)=2000(1- 0.2)^t\\\\f(t)=2000(0.8)^t[/tex]
(e)Since we require the worth of the computer after 4 years,
t=4 years
[tex]f(4)=2000(0.8)^4\\f(4)=\$819.20[/tex]
Prove that : sin^4(2x)=3/8-1/2cos4x+1/8cos8x
Someone plzz help!!!
The volume of a triangular prism is increased by a factor of 8.
By what factor is the surface area of the figure increased?
o 2
o 4
016
o 24
What is the answer for this one ?
4x+3y=20 2x+y=7
Answer:
x = 1/2 , y = 6
Explanation:
Step 1 - Align the equations and multiply the second row by 2
4x + 3y = 20
2x + y = 7
4x + 3y = 20
4x + 2y = 14
Step 2 - Subtract them both
4x + 3y = 20
4x + 2y = 14
y = 6
So, y = 6
Step 3 - Substitute y into the first equation
4x + 3y = 20
4x + 3(6) = 20
4x + 18 = 20
Step 4 - Subtract 18 from both sides
4x + 18 = 20
4x + 18 - 18 = 20 - 18
4x = 2
Step 5 - Divide both sides by 4
4x = 2
4x / 4 = 2 / 4
x = 2/4
So, x = 1/2
Find the area of the smaller sector.
Round to the nearest tenth.
Help needed fast
Answer:
About 22.2 square feet
Step-by-step explanation:
First, you need to find the area of the full circle. The area of a circle is \pi r^2, which in this case is:
[tex]\pi r^2 = \pi \cdot 7.13^2\approx 159.628[/tex]
Now, since the sector is only 50 out of the total 360 degrees in a circle, you need to multiply this value by 50/360, which yields and area of about 22.2 square feet. Hope this helps!
what is 3 43/ 100 as a decimal number.
Answer:
3.43
Step-by-step explanation:
3 is the whole number and 43 out of 100 is a standard fraction that can simply be stated as 0.43. Hope this helps!
Answer:
3.43
Step-by-step explanation:
Used calculator.
The lengths of nails produced in a factory are normally distributed with a mean of 5.02 centimeters and a standard deviation of 0.05 centimeters. Find the two lengths that separate the top 6% and the bottom 6%. These lengths could serve as limits used to identify which nails should be rejected. Round your answer to the nearest hundredth, if necessary.
Answer:
The length that separates the top 6% is 5.1 centimeters.
The length that separates the bottom 6% is 4.94 centimeters.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 5.02, \sigma = 0.05[/tex]
Find the two lengths that separate the top 6% and the bottom 6%.
Top 6%:
The 100-6 = 94th percentile, which is X when Z has a pvalue of 0.94. So X when Z = 1.555.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.555 = \frac{X - 5.02}{0.05}[/tex]
[tex]X - 5.02 = 1.555*0.05[/tex]
[tex]X = 5.1[/tex]
So the length that separates the top 6% is 5.1 centimeters.
Bottom 6%:
The 6th percentile, which is X when Z has a pvalue of 0.06. So X when Z = -1.555.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.555 = \frac{X - 5.02}{0.05}[/tex]
[tex]X - 5.02 = -1.555*0.05[/tex]
[tex]X = 4.94[/tex]
The length that separates the bottom 6% is 4.94 centimeters.
Graph the equation below by plotting the
y-intercept and a second point on the
line. When you click Done, your line will
appear
Answer:
Plot the y-intercept at (0, 2). Plot your second point at (-1, -1).
Step-by-step explanation:
I attached an image of what the finished graph should look like when you press done. *rotate the image so the grey is on the bottom*
True or false: as the value of cosx decreases towards 0, the value of secx increases towards infinity
Answer:
True
Step-by-step explanation:
What is the value of x to the nearest tenth? gradpoint
Answer:
5
Step-by-step explanation:
y=2x−4y=−12x+1 Question 1 options: a) (3, 2) b) (0, 2) c) (2, 0) d) (2, 3)
A fair die is rolled twice, with outcomes X for the first roll and Y for the second roll. Find the moment generating function MX`Y ptq of X ` Y . Note that your answer should be a function of t and can contain unsimplified finite sums.
Answer:
[tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]
Step-by-step explanation:
The objective is to find the moment generating function of [tex]M_{X+Y}(t) \ of \ X+Y[/tex].
We are being informed that the fair die is rolled twice;
So; X to be the value for the first roll
Y to be the value of the second roll
The outcomes of X are: X = {1,2,3,4,5,6}
Where ;
[tex]P (X=x) = \dfrac{1}{6}[/tex]
The outcomes of Y are: y = {1,2,3,4,5,6}
Where ;
[tex]P (Y=y) = \dfrac{1}{6}[/tex]
The outcome of Z = X+Y
[tex]= \left[\begin{array}{cccccc}(1,1)&(1,2)&(1,3)&(1,4)&(1,5)&(1,6)\\ (2,1)&(2,2)&(2,3)&(2,4)&(2,5)&(2,6)\\ (3,1)&(3,2)&(3,3)&(3,4)&(3,5)&(3,6) \\ (4,1)&(4,2)&(4,3)&(4,4)&(4,5)&(4,6) \\ (5,1)&(5,2)&(5,3)&(5,4)&(5,5)&(5,6) \\ (6,1)&(6,2)&(6,3)&(6,4)&(6,5)&(6,6) \end{array}\right][/tex]
= [2,3,4,5,6,7,8,9,10,11,12]
Here;
[tex]P (Z=z) = \dfrac{1}{36}[/tex]
∴ the moment generating function [tex]M_{X+Y}(t) \ of \ X+Y[/tex]is as follows:
[tex]M_{X+Y}(t) \ of \ X+Y[/tex] = [tex]E(e^{t(X+Y)}) = E(e^{tz})[/tex]
⇒ [tex]\sum \limits^{12}_ {z=2 } et ^z \ P(Z=z)[/tex]
= [tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]
g You run a regression analysis on a bivariate set of data ( n = 14 ). With ¯ x = 27.7 and ¯ y = 26.5 , you obtain the regression equation y = 0.495 x − 14.914 with a correlation coefficient of r = 0.39 . You want to predict what value (on average) for the response variable will be obtained from a value of 110 as the explanatory variable. What is the predicted response value?
Answer:
Predicted response value = 39.536
Note that this predicted response value will most likely be far from the actual response value because the correlation coefficient of the regression equation used (r = 0.39) is too far away from 1.
Step-by-step explanation:
The response variable is the dependent variable (y) whose value is obtained from the expression involving the independent variable (x).
For this question, although the correlation coefficient, r = 0.39, is far from 1, the regression equation is
y = 0.495x - 14.914
The predicted response value will be obtained from the explanatory variable and the regression equation
x = 110
y = 0.495x - 14.914
y = (0.495×110) - 14.914 = 39.536
Note that this predicted response value will most likely be far from the actual response value because the correlation coefficient of the regression equation used (r = 0.39) is too far away from 1.
Hope this Helps!!!
write this small number in standard form. 0.00078
Answer:
78/100000
Hope it helps you
Bonita said that the product of 5/6 x 1 2/3 is 7/3.
How can you tell that her answer is wrong.
Answer:
Bonita's product is too large
Step-by-step explanation:
The two factors in the problem are (5/6) and (5/3). The factor 5/6 is less than 1, ensuring that the product will be less than 5/3.
Bonita's result of 7/3 is more than 5/3, so is too large to be the product.
4) If the data below contained an outlier, which coordinate would best represent the outlier?
(MGSE8.SP.1)
100
90
80
70
60
50
Weight
(kgs)
40
30
20
10
0
0
200
250
100 150
Height (cms)
A. (150, 60)
B. (50,20)
C. (200, 100)
D. (250, 80)
Answer:
D. (250, 80)
Step-by-step explanation:
a) Outliers are values that "lie outside" the other values in a dataset, because their values are "far away" from the main group of data.
b) In this case, the values of A, B, and C have ratios of their coordinates of about 2.5, but the coordinate ratio of D is more than 3. This makes it to lie far away from the group of data, and therefore an outliner.
c) The Ratios of the Coordinate Values are calculated as follows: A = 2.5 (150/60), B = 2.5 (50/20), C = 2 (200/100), while D = 3.125 (250/80).
#2 Jamal is an apprentice on a boat on Long Island Sound. He is helping the captain collect samples of
marine life for an environmental study, and the captain is teaching him about nautical navigation.
When the boat leaves the environmental station, it will return to its home port 9 nautical miles away.
If
the boat maintains a constant speed of 15 knots (nautical miles per hour), how many minutes will the
trip take?
Answer:
The trip will take 36 minutes.
Step-by-step explanation:
This question can be solved using a rule of three.
The boat maintains a constant speed of 15 knots (nautical miles per hour). How many minutes it will take to return to its home port 9 nautical miles away?
So in 60 minutes, 15 nautical miles. How many minutes for 9 nautical miles?
60 minutes - 15 nautical miles
x minutes - 9 nautical miles
[tex]15x = 60*9[/tex]
[tex]x = \frac{60*9}{15}[/tex]
[tex]x = 36[/tex]
The trip will take 36 minutes.
