g A psychic was tested for extrasensory perception (ESP). The psychic was presented with cards face down and asked to determine if each of the cards was one of four symbols: a star, cross, circle, or square. Let p represent the probability that the psychic correctly identified the symbols on the cards in a random trial. How large a sample n would you need to estimate p with margin of error 0.01 and 95% confidence?

Answers

Answer 1

Answer:

Step-by-step explanation:

Hello!

The objective is to test ESP, for this, a psychic was presented with cards face down and asked to determine if each of the cards was one of four symbols: a star, cross, circle, square.

Be X: number of times the psychic identifies the symbols on the cards correctly is a size n sample.

p the probability that the psychic identified the symbol on the cards correctly

You have to calculate the sample size n to estimate the proportion with a confidence level of 95% and a margin of error of d=0.01

The CI for the population proportion is constructed "sample proportion" ± "margin of error" Symbolically:

p' ± [tex]Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex]

Where  [tex]d= Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex] is the margin of error. As you can see, the formula contains the sample proportion (it is normally symbolized p-hat, in this explanation I'll continue to symbolize it p'), you have to do the following consideration:

Every time the psychic has to identify a card he can make two choices:

"Success" he identifies the card correctly

"Failure" he does not identify the card correctly

If we assume that each symbol has the same probability of being chosen at random P(star)=P(cross)=P(circle)=P(square)= 1/4= 0.25

Let's say, for example, that the card has the star symbol.

The probability of identifying it correctly will be P(success)= P(star)= 1/4= 0.25

And the probability of not identifying it correctly will be P(failure)= P(cross) + P(circle) + P(square)= 1/4 + 1/4 + 1/4= 3/4= 0.75

So for this experiment, we'll assume the "worst case scenario" and use p'= 1/4 as the estimated probability of the psychic identifying the symbol on the card correctly.

The value of Z will be [tex]Z_{1-\alpha /2}= Z_{0.975}= 1.96[/tex]

Now using the formula you have to clear the sample size:

[tex]d= Z_{1-\alpha /2} * (\sqrt{\frac{p'(1-p')}{n} } )[/tex]

[tex]\frac{d}{Z_{1-\alpha /2}} = \sqrt{\frac{p'(1-p')}{n} }[/tex]

[tex](\frac{d}{Z_{1-\alpha /2}})^2 =\frac{p'(1-p')}{n}[/tex]

[tex]n*(\frac{d}{Z_{1-\alpha /2}})^2 = p'(1-p')[/tex]

[tex]n = p'(1-p')*(\frac{Z_{1-\alpha /2}}{d})^2[/tex]

[tex]n = (0.25*0.75)*(\frac{1.96}{0.01})^2= 7203[/tex]

To estimate p with a margin of error of 0.01 and a 95% confidence level you have to take a sample of 7203 cards.

I hope this helps!

Answer 2

Answer:

The sample size should be 6157

Step-by-step explanation:

Given that the margin of error (e) = ± 0.01 and the confidence (C) = 95% = 0.95.

Let us assume that the guess p = 0.25 as the value of p.

α = 1 - C = 1 - 0.95 = 0.05

[tex]\frac{\alpha }{2} =\frac{0.05}{2}=0.025[/tex]

The Z score of α/2 is the same as the z score of 0.475 (0.5 - 0.025) which is 1.96. Therefore [tex]Z_\frac{\alpha }{2}=Z_{0.025}=1.96[/tex]

To determine the sample size n, we use the formula:

[tex]Z_{0.025}*\sqrt{\frac{p(1-p)}{n} }\leq e\\Substituting:\\1.96*\sqrt{\frac{0.2(1-0.2)}{n} } \leq 0.01\\\sqrt{\frac{0.2(0.8)}{n} }\leq \frac{1}{196}\\\sqrt{0.16} *196 \leq \sqrt{n}\\78.4\leq \sqrt{n}\\ 6146.56\leq n\\n=6157[/tex]


Related Questions

What are the solutions of the equation 9x^4 – 2x^2 – 7 = 0? Use u substitution to solve

Answers

Answer:

[tex]x=1\\x=-1[/tex]

Step-by-step explanation:

[tex]9x^{4} -2x^{2} -7=0\\y=x^{2} \\9y^{2} -2y-7=0\\y=\frac{2\pm\sqrt{(-2)^{2} -4*9(-7)} }{2*9} =\frac{2\pm\sqrt{4+252} }{18} =\frac{2\pm\sqrt{256} }{18}[/tex]

[tex]\sqrt{256} =16[/tex]

[tex]y=\frac{2+16}{18} =\frac{18}{18} =1 \\or \\y=\frac{2-16}{18} =-\frac{14}{18} =-\frac{7}{9}[/tex]

[tex]x^{2} = 1 \\or \\x^{2} =-\frac{7}{9}[/tex]

[tex]x=\pm 1[/tex]

[tex]x^{2} =-\frac{7}{9}[/tex] has no solution since fot all [tex]x[/tex] on the real line, [tex]x^{2} \geq 0[/tex] and [tex]-\frac{7}{9} < 0.[/tex]

tank contains 20002000 liters​ (L) of a solution consisting of 112112 kg of salt dissolved in water. Pure water is pumped into the tank at the rate of 1212 ​L/s, and the mixturelong dash—kept uniform by stirringlong dash—is pumped out at the same rate. How long will it be until only 88 kg of salt remains in the​ tank?

Answers

The time taken in draining salt so that only 88 kg of salt remains in tank will be 35.71 sec.

It is given that a tank contains 2000 liters of a solution consisting 112 kg of salt is dissolved in water. Pure water is then pumped at rate of 12 L/sec.

We have to find out that how long it will take to drain out salt such that only 88kg of salt remains in tank.

What will be the amount of water flow ; if a water flows for 4 hours at constant speed of 120 liter /hour ?

The amount of water flow will be 120 liter / hour × 4 hour or 120 × 4 liter or 480 liters.

As per the question ;

In 2000 liters solution there is 112 kg salt.

The pumping speed of water into tank = 12 L/s

The salt pumping per second will be ;

= ( 12L/s × 112kg salt ) / 2000 L

= 0.672 Kg salt/sec

This means that 0.672 kg per second salt comes out .

It should be found that the amount of salt that must be drained so that only 88 kg of salt remain.

So , the amount of salt drained out will be ; (x kg)

112kg salt - x kg salt = 88 kg salt

⇒ x kg salt = 112 - 88

x kg salt = 24 kg

The time taken until only 88 kg of salt remains in the​ tank will be ;

= 24 / 0.672

= 35.71 sec

Thus , the time taken in draining salt so that only 88 kg of salt remains in tank will be 35.71 sec.

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Give your answers in pi

Answers

Answer:

36π

Step-by-step explanation:

area=πr²

=πx6x6

6x6=36

area = 36π

Complete the statements with equal to, greater than, or less than. 5 6 × 6 9 is ? 5 6 . 6 × 5 6 is ? 5 6 . 5 6 × 9 9 is ? 5 6 . 5 6 × 8 7 is ? 5 6 . 7 7 × 5 6 is ? 5 6 . 5 6 × 5 6 is ? 5 6 .

Answers

Answer:

someone already answered

Step-by-step explanation:

srry

When Janelle woke up, it was –3 degrees Fahrenheit outside. As the morning progressed, the temperature rose 2 degrees every hour. Which line on the graph could represent this scenario? a(x) f(x) g(x) h(x)

Answers

Answer: g(x)

Step-by-step explanation:

The graph represented by the degrees Fahrenheit outside is y = 2x - 3 where g ( x ) = 2x - 3

What is an Equation of a line?

The equation of a line is expressed as y = mx + b where m is the slope and b is the y-intercept

And y - y₁ = m ( x - x₁ )

y = y-coordinate of second point

y₁ = y-coordinate of point one

m = slope

x = x-coordinate of second point

x₁ = x-coordinate of point one

The slope m = ( y₂ - y₁ ) / ( x₂ - x₁ )

Given data ,

Let the equation of line be represented as A

Now , the value of A is

Slope m = 2

Given that it was -3 degrees Fahrenheit outdoors when Janelle woke up. The temperature increased by 2 degrees every hour as the morning went on. It implies,

Temperature at start: -3

Changes occur at a rate of 2 degrees each hour.

A line's slope intercept form is y = 2x - 3

Hence , the equation of line is y = 2x - 3 and the graph depicted is g ( x )

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The complete question is attached below :

When Janelle woke up, it was –3 degrees Fahrenheit outside. As the morning progressed, the temperature rose 2 degrees every hour. Which line on the graph could represent this scenario?

a(x)

f(x)

g(x)

h(x)

What’s the correct answer for this?

Answers

Answer:

E:

Step-by-step explanation:

The equation of circles is

(x-a)²+(y-b)²=r²

Where

Center = (a,b) = (-6,-3) and r = 12

Now

The equation becomes

(x+6)²+(x+3)²=144

A 10 foot tree create a shadow that is 15 feet long. Find the angle of elevation of the sun

Answers

The angle of elevation of the sun when a 10-foot tree creates a shadow that is 15 feet long  is 33.69 degrees

To find the angle of elevation of the sun, we can use trigonometry and the concept of similar triangles.

Given that:

The tree's height is 10 feet.

The length of the shadow is 15 feet.

Let's assume that the tree's height is "h"  feet.

Length of its shadow is represented by "s" feet

The angle of elevation of the sun is the angle between the ground and the line from the top of the tree to the tip of its shadow.

The angle can be determined using the tangent function.

[tex]tan\theta[/tex] = [tex]\dfrac{h}{s}[/tex]

Now, substitute the given values:

[tex]tan\theta[/tex]= [tex]\dfrac{10}{15}[/tex]

[tex]tan\theta[/tex] = [tex]\dfrac{2}{3}[/tex]

The angle of elevation can be obtained by  taking the inverse tangent of 2/3

angle of elevation =[tex]\tan^-1\dfrac{2}{3}[/tex]

angle of elevation ≈ 33.66 degrees

So, the angle of elevation of the sun is approximately 33.69 degrees.

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When Sunita weighed herself on Monday, she found that she had gained 1 1/4 kg. Earlier her weight was 46 3/8 kg. What was her weight on Monday? Please give me Statements! Please Do it fast(Its ok if you dont do it fast ok its not like that much of an urgent) #GoAwayCoronaVirus

Answers

Answer:

[tex]47\frac{5}{8}[/tex]

Step-by-step explanation:

Weight from before + Weight gained

[tex]46\frac{3}{8} +1\frac{1}{4}[/tex]

Convert to improper fractions.

[tex]371/8 + 5/4[/tex]

Find the common denominator.

[tex]371/8 + 10/8[/tex]

Add.

[tex]381/8[/tex]

Convert to a mixed fraction.

[tex]47\frac{5}{8}[/tex]

Answer:

47 5/8 kg

Step-by-step explanation:

Ealier weight + gained weight = Monday's weight

46 3/8 + 1 1/4

= 371/8 + 5/4

= 371/8 + 10/8

= 381/8

= 47 5/8 kg

In a lottery, you pay $1 and pick a number from 000 to 999. If your number comes up, you win $350, which is a profit of $349. If you lose, you lose $1. Your probability of winning is 0.001. What is the expected value of your profit

Answers

Answer:

The expected value of profit is -$0.65.

Step-by-step explanation:

The rules of the lottery are as follows:

You pay $1 and pick a number from 000 to 999.If your number comes up, you win $350, which is a profit of $349.If you lose, you lose $1.

The probability of winning is, P (W) = 0.001.

Then the probability of losing will be,

P (L) = 1 - P (W)

       = 1 - 0.001

       = 0.999

Let the random variable X represent the amount of profit.

The probability distribution table of the lottery result is as follows:

Result      X        P (X)

Win      +349     0.001

Lose         -1       0.999

The formula to compute the expected value of X is:

[tex]E(X)=\sum X\cdot P(X)[/tex]

Compute the expected value of profit  as follows:

[tex]E(X)=\sum X\cdot P(X)[/tex]

         [tex]=(349\times 0.001)+(-1\times 0.999)\\\\=0.349-0.999\\\\=-0.65[/tex]

Thus, the expected value of profit is -$0.65.

F(x)=2x-6 and g(x)=3x+9,find (f+g)(x)

Answers

Answer: 5x-3

Step-by-step explanation:

(f+g)(x) means f(x)+g(x). Knowing this, we add the 2 functions together.

2x-6+3x+9

5x-3

The soup produced by a company has a salt level that is normally distributed with a mean of 5.4 grams and a standard deviation of 0.3 grams. The company takes readings of every 10th bar off the production line. The reading points are 5.8, 5.9, 4.9, 5.2, 5.0, 4.9, 6.2, 5.1, 5.7, 6.1. Is the process in control or out of control and why?

Answers

Answer:

Step-by-step explanation:

The mean of the reading points is

Mean = (5.8 + 5.9 + 4.9 + 5.2 + 5.0 + 4.9 + 6.2 + 5.1 + 5.7 + 6.1)/10 = 5.48

The process is out of control if the mean salt level of the readings is greater than 5.4

For the null hypothesis,

µ = 5.4

For the alternative hypothesis,

µ > 5.4

This is a right tailed test.

Since the population standard deviation is given, z score would be determined from the normal distribution table. The formula is

z = (x - µ)/(σ/√n)

Where

x = sample mean

µ = population mean

σ = population standard deviation

n = number of samples

From the information given,

µ = 5.4

x = 5.48

σ = 0.3

n = 10

z = (5.48 - 5.4)/(0.3/√10) = 0.84

Looking at the normal distribution table, the probability corresponding to the z score is 0.7996

The probability value to the right of the z score is 1 - 0.7996 = 0.2

Assuming a significance level of 0.05

Since alpha, 0.05 < than the p value, 0.2, then we would fail to reject the null hypothesis. Therefore, At a 5% level of significance, we can conclude that the process is not out of control. If we had rejected the null hypothesis, then our conclusion would be that the process is out of control.

A student's tuition was $1200. A loan was obtained for 5/6 of the tuition. How much was the loan?

Answers

Answer:

the loan was 1000

Step-by-step explanation:

Take the tuition and multiply by 5/6

1200 *5/6

1200/6 *5

200 *5

1000

Answer:

$1000

Step-by-step explanation:

In order to find 5/6 of the tuition, we just need to multiply the 2 values together.

5/6*1200

Note that 1200 = 1200/1

5/6*1200/1

When multiplying fractions, we can multiply the numerators together, and the denominators together.

5*1200/6*1

6000/6

Divide.

1000

Therefore, the loan was $1000.

two lines intersect is more than one point

Answers

Answer:

FALSE

Step-by-step explanation:

two lines can be parallel- no intersectstwo lines intersect- one point

The HCF of two numbers is 11, and their L.C.M is 368. If one number is 64, then the other number is ….

Answers

Answer:

63.45

Step-by-step explanation:

First, it should be noted that the question is incorrect because 64 can't be divided by 11 but assuming that the question is correct, the solution is as follows

Given

LCM = 368

HCF = 11

One number = 64

Required

The other number

Let both numbers be represented by m and n, such that

[tex]m = 64[/tex]

From laws of HCF and LCM

The product of both numbers = Product of HCF and LCM

i.e.

[tex]m * n = HCF * LCM[/tex]

By substituting 68 for m; 368 for LCM and 11 for HCF

[tex]m * n = HCF * LCM[/tex] becomes

[tex]64 * n = 368 * 11[/tex]

[tex]64n = 4048[/tex]

Divide both sides by 64

[tex]\frac{64n}{64} = \frac{4048}{64}[/tex]

[tex]n = \frac{4048}{64}[/tex]

[tex]n = 63.25[/tex]

Express this number in scientific notation. 5.3×104+4.7×104

Answers

Answer:

for [tex]5.3 * 10^4 + 4.7 * 10^4[/tex] the answer would be [tex]1 * 10^5[/tex]

Step-by-step explanation:

After adding like terms we would get [tex]10^4 *10[/tex]

Then we use the exponent rule and get [tex]10^1^+^4[/tex]

Which after adding would result in [tex]10^5[/tex]

help asap giving branlist!!!

Answers

Answer:

option 2

Step-by-step explanation:

Because (0, 900) is a point on the line it means that it costs $900 to make the commercial. A slope of 110 means that they pay $110 every time it's aired so the answer is Option 2.

Please answer this question I give brainliest thank you! Number 16

Answers

Answer:

4a

Step-by-step explanation:

The mean is found by adding all of the data set together and then dividing by the amount of individual pieces of data in the set.

(2+3+3+8) = 16

16/4=4

The answer is 4a.

leave answer in simplest radical form

Answers

Answer:

[tex]\dfrac{5\pm\sqrt{47}}{6}[/tex]

Step-by-step explanation:

Let's start by setting y to 0 to find the roots of the quadratic.

[tex]x=\dfrac{5\pm \sqrt{25+12}}{6}=\\\\\dfrac{5\pm\sqrt{47}}{6}[/tex]

Hope this helps!

jack is investing 5000 in an account that earns 4% interest compounded annually. Determine to the nearest month when the investment will be worth 8000

Answers

Answer:

The nearest time is 15 years or 180 months

Please answer this correctly

Answers

Answer:

40 - 59 ⇒ 6

60 - 79 ⇒ 5

Answer:

40-59: 6

60-79: 5

Step-by-step explanation:

If you just added up, you can find all the values.

Classify the triangle by its​ sides, and then by its angles.
60 degrees
60 degrees
60 degrees
4 ft
4 ft
4 ft
Classified by its​ sides, the triangle is​ a(n)

equilateral
scalene
isosceles
triangle.
Classified by its​ angles, the triangle is​ a(n)

obtuse
acute
right
triangle.

Answers

Answer:

Equilateral, acute

Step-by-step explanation:

Equilateral triangles have all sides the same length (all sides are 4 ft in this triangle, so it is equilateral).

Acute triangles have no angles that are greater than or equal to 90 degrees (all angles are 60, which is less than 90, so it is acute).

A local coffee house surveyed 317 customers regarding their preference of chocolate chip or cranberry walnut scones . 150 customers prefer the Cranberry Walnut Scones . 81 customers who responded were males and prefer the Chocolate Chip Scones . 172 female customers responded . Find the probability that a customer chosen at random will be a male or prefer the Chocolate Chip Scones .

1. 25.6%
2. 24.1%
3. 72.9%
4. 98.4%

Answers

Answer:

3. 72.9%

Step-by-step explanation:

Let's call M the event that the customer is male and C the event that the customer prefer chocolate chips Scones.

So, the probability P(M∪C) that a customer chosen at random will be a male or prefer the Chocolate Chip Scones is calculated as:

P(M∪C) = P(M) + P(C) - P(M∩C)

Then, there are 145 males (317 customer - 172 females = 145 males), so the probability that the customer is a males is:

P(M) = 145/317 = 0.4574

There are 167 customers that prefer chocolate chips Scones ( 317 customers - 150 customers that prefer the Cranberry Walnut Scones = 167), so the probability that a customer prefer chocolate chips Scones is:

P(C) = 167/317 = 0.5268

Finally, 81 customers were males and prefer the Chocolate Chip Scones, so the probability that a customer will be a male and prefer chocolate  chip scones is:

P(M∩C) = 81/317 = 0.2555

Therefore,  P(M∪C) is equal to:

P(M∪C) = 0.4574 + 0.5268 - 0.2555

P(M∪C) = 0.7287

P(M∪C) = 72.9%

Answer:

3. 72.9%

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Desired outcomes:

Male or prefers the Chocolate Chip Scones. That is, males and females who prefer the Chocolate Chip Scones.

There are 172 female customers and 317-172 = 145 male customers.

150 customers prefer the Cranberry Walnut Scones. So 317 - 150 = 167 customers prefer the Chocolate Chip Scones.

81 of those are male, so 167 - 81 = 86 are female.

So the total of desired outcomes is 86 + 145 = 231

Total outcomes:

317 total customers.

Probability:

231/317 = 0.729

So the correct answer is:

3. 72.9%

What is the size of angle YXZ?

Answers

We have a right triangle and we're given the leg lengths.  

tan X = |YZ| / |XZ| = 20/8 = 5/2

X = arctan(5/2) = 68.2°

Answer: 68.2°

tan X = YZ / XZ = 20/8 = 5/2

X = arctan(5/2) = 68.2°

Answer: 68.2°

What’s the correct answer for this question?

Answers

Answer:

107 meters

Step-by-step explanation:

Central angle = 123°

In radians

123° = 123π/180

123° = 2.147 radians

Putting in formula

S = r∅

S = (50)(2.147)

S = 107 meters

The height of a ball t seconds after it is thrown upward from a height of 6 feet and with an initial velocity of 80 feet per second is f (t) = -16t2 + 80t + 6. (a) Verify that f(2) = f(3).

Answers

Answer:

f(2) = f(3) = 102 ft

Step-by-step explanation:

The height f at t = 2 seconds is given by:

[tex]f(t) = -16t^2 + 80t + 6\\f(2) = -16*2^2 + 80*2 + 6\\f(2)=-64+160+6\\f(2)=102\ ft[/tex]

The height f at t = 3 seconds is given by:

[tex]f(t) = -16t^2 + 80t + 6\\f(3) = -16*3^2 + 80*3 + 6\\f(3)=-144+240+6\\f(3)=102\ ft[/tex]

For both t =2 and t =3, the expression results in a height of 102 ft, therefore f(2) = f(3) = 102 ft.

In order to solve for the variable in the equation 2 (x + 3) + 5 x = 3 (2 x minus 1), Jaleesa begins by applying the distributive property, then combines like terms. Which equation is the result of these steps?

Answers

Answer:

7x+6 = 6x-3

Step-by-step explanation:

2 (x + 3) + 5 x = 3 (2 x - 1)

Distribute

2x+6+5x = 6x-3

Combine like terms

7x+6 = 6x-3

Answer:

7x + 6 = 6x - 3                                  Option A

Step-by-step explanation:

Now Jalesa wants to simplify this equation.

Firstly applying the distributive property

Distribute the 2 over the parenthesis and distribute the over the parenthesis

that is,

2*x + 2*3 + 5x = 3*2x - 3*1

2x + 6 + 5x = 6x - 3

After that combine like terms

2x + 5x + 6 = 6x - 3

7x + 6 = 6x - 3

Result is:

7x + 6 = 6x - 3

That's the final answer.

The Sky Train from the terminal to the rental car and longterm parking center is supposed to arrive every eight minutes. The waiting times for the train are known to follow a uniform distribution. What is the average waiting time (in minutes)

Answers

Answer:

Average waiting time = 4 minutes

Step-by-step explanation:

From this question, we are told that the sky train is supposed to arrive every 8 minutes.

Thus, the waiting time of the passengers for the train = 8 minutes.

Then, the average waiting time is simply the mean or 50th percentile of the total waiting time.

So, average waiting time = 50% × 8

Average waiting time = 4 minutes

If \\(z_1=3+2i\\) and \\(z_2=4+3i\\) and are complex numbers, find \\(z_1z_2\\)

Answers

[tex]z_1z_2=(3+2i)(4+3i)=3\cdot4+2i\cdot4+3\cdot3i+2i\cdot3i[/tex]

[tex]z_1z_2=12+8i+9i+6i^2[/tex]

[tex]i^2=-1[/tex], so

[tex]z_1z_2=12+8i+9i-6=\boxed{6+17i}[/tex]

A humanities professor assigns letter grades on a test according to the following scheme. A: Top 12% of scores B: Scores below the top 12% and above the bottom 61% C: Scores below the top 39% and above the bottom 21% D: Scores below the top 79% and above the bottom 6% F: Bottom 6% of scores Scores on the test are normally distributed with a mean of 67.7 and a standard deviation of 7.8. Find the minimum score required for an A grade. Round your answer to the nearest whole number, if necessary.

Answers

Answer:

The minimum score required for an A grade is 77.

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 = 67.7, \sigma = 7.8[/tex]

Find the minimum score required for an A grade.

Top 12% of scores get an A.

100-12 = 88th percentile.

The 88th percentile of scores is the minimum required for an A grade. This score is X when Z has a pvalue of 0.88. So X when Z = 1.175.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.175 = \frac{X - 67.7}{7.8}[/tex]

[tex]X - 67.7 = 7.8*1.175[/tex]

[tex]X = 76.865[/tex]

Rounding to the nearest whole number:

The minimum score required for an A grade is 77.

Score: 4 of 8 pts
TA
23.1.59
A ball is thrown upward and outward from a height of 5 feet. The height of the ball, f(x), in feet, can be mo
f(x) = -0.2x² +2.1x+5
where x is the ball's horizontal distance, in feet from where it was thrown. Use this model to solve parts (
a. What is the maximum height of the ball and how far from where it was thrown does this occur?
The maximum height is feet, which occurs feet from the point of release
(Round to the nearest tenth as needed.)​

Answers

Answer:

  10.5 ft high

  5.3 ft horizontally

Step-by-step explanation:

The equation can be written in vertex form to answer these questions.

  f(x) = -0.2(x² -10.5x) +5

  f(x) = -0.2(x² -10.5x +5.25²) +5 +0.2(5.25²)

  f(x) = -0.2(x -5.25)² +10.5125

The vertex of the travel path is (5.25, 10.5125).

The maximum height is 10.5 feet, which occurs 5.3 feet (horizontally) from the point of release.

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