I NEED ANSWER ASAP LOTS OF POINTS

Given a mean score of 1150, standard deviation of 90, and 500 participants, solve the following problem. Using this data and the

expeople1 [14]

Answer:

1. 1056.67

2. 29th percentile.

3. 79

4. 77

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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 p-value, we get the probability that the value of the measure is greater than X.

Mean score of 1150, standard deviation of 90

This means that $\mu = 1150, \sigma = 90$

1. What is the score for someone in the 15th percentile?

This is X when Z has a p-value of 0.15, so X when Z = -1.037.

$Z = \frac{X - \mu}{\sigma}$

$-1.037 = \frac{X - 1150}{90}$

$X - 1150 = -1.037*90$

$X = 1056.67$

2. What is the percentile rank of someone with a score of 1100?

This is the p-value of Z when X = 1100. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1100 - 1150}{90}$

$Z = -0.555$

$Z = -0.555$ has a p-value of 0.29, so 29th percentile.

3. How many students have scores of 1060 or greater?

The proportion is 1 subtracted by the p-value of Z when X = 1060. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1060 - 1150}{90}$

$Z = -1$

$Z = -1$ has a p-value of 0.1587.

Out of 500:

0.1587*500 = 79

79 is the answer.

4. How many students scored between 1200 and 1250?

The proportion is the p-value of Z when X = 1250 subtracted by the p-value of Z when X = 1200. So

X = 1250

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1250 - 1150}{90}$

$Z = 1.1$

$Z = 1.1$ has a p-value of 0.8643.

X = 1200

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1200 - 1150}{90}$

$Z = 0.555$

$Z = 0.555$ has a p-value of 0.7106

0.8643 - 0.7106 = 0.1537

Out of 500:

0.1537*500 = 77

77 is the answer.

7 0

3 years ago

Please help!!! Find the domain of the function y = 2 cot(5∕8x).

anastassius [24]

Answer:

B) All real numbers except 0 and integer multiples of 8π∕5

Step-by-step explanation:

Cotangent function:

The cotangent function is given by:

$y = \cot{ax} = \frac{\cos{ax}}{\sin{ax}}$

Domain:

All real values except those at which:

$\sin{ax} = 0$

The sine is 0 for 0 and all integer multiples of $\frac{1}{a}$

In this question:

$a = \frac{5}{8}$ , so the values outside the domain are 0 and the integer multiples of $\frac{8}{5}$ . Then the correct answer is given by option b.

6 0

3 years ago

Plot the point (−1/2, −5/2) on the coordinate plane.

Pavel [41]

That would be at quadrant to so you want to plot -1 and then half a box to the left. Then you want to point -5 and then just go up half. Hope this helps

6 0

3 years ago

Read 2 more answers

Estimate 7.411*47hhhhhhhhhhhhh

jenyasd209 [6]

7*50=350

350 is da answer so yeah

6 0

3 years ago

1. Ten times the sum of -270 and a number gives -20.

Svetach [21]

9514 1404 393

Answer:

equation: 10(-270 +n) = -20
number: 268

Step-by-step explanation:

If n represents the number, we have ...

10(-270 +n) = -20 . . . an equation for n

__

The solution can be found as ...

-270 +n = -2 . . . . . divide by 10

n = 268 . . . . . . . add 270

The number is 268.

6 0

3 years ago