The next two questions (18 and 19) refer to the following:

The heights of elementary school students are known to follow a normal distribution with mean 121 cm and standard deviation 5 cm.

Question 18 (1 point)

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What is the 60^th percentile of heights of elementary school students?

Question 18 options:

Question 19 (1 point)

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A random sample of eight elementary school students is selected. What is the probability that their average height is between 122 cm and 123 cm?

Question 19 options:

8.66 Significance Test for Exergaming in Canada. Refer to exercise 8.64. Use a significance test to compare the proportions. Write a short statement interpreting this result.

8.64  Exergaming in Canada. Exergames are active video games such as rhythmic dancing games, virtual bicycles, balance board simulators, and virtual sports simulators that require a screen and a console. A study of exergaming practiced by students from grades 10 and 11 in Montreal, Canada, examined many factors related to participation in exergaming.²² Of the 358 students who reported that they stressed about their health, 29.9% said that they were exergamers. Of the 851 students who reported that they did not stress about their health, 20.8% said that they were exergamers.

The National Center for Education Statistics reports the following statistics for surveys of 12,320 female college students and 9,184 male college students.

36% of females work 16-25 hours per week

38% of males work 16-25 hours per week

Suppose two students are selected with replacement. Find the probability that the first student is a female that works 16-25 hours per week and the second student is a female that works 16-25 hours per week. Round your answer to three decimal places.

Are the events dependent or independent?

Are the two events mutually exclusive? Event F: the subject is a female     Event G: the subject is a graduate student

2020 Election ~ Bernie Sanders is a popular presidential candidate among university students for the 2020 presidential election. Leading into Michigan’s presidential primary election in 2020, a journalist, Lauren took a random sample of 11,834 university students and found that 8,211 of them support Bernie Sanders.

Using this data, Lauren wants to estimate the actual proportion of university students who support Bernie Sanders.

To calculate the required sample size, what value of Z* should we use in the formula below to calculate a 90% confidence interval within 4.62 percentage points? Give your answer to 4 decimal places.

n= p* (1-p*) (z*/ME)^2

2020 Election ~ Bernie Sanders is a popular presidential candidate among university students for the 2020 presidential election. Leading into Michigan’s presidential primary election in 2020, a journalist, Lauren took a random sample of 12,887 university students and found that 8,014 of them support Bernie Sanders.

Using this data, Lauren wants to estimate the actual proportion of university students who support Bernie Sanders.

To calculate the required sample size, what value ofME. should we use in the formula below to calculate a 90% confidence interval within 8.84 percentage points? Give your answer to 4 decimal places.

n=p*(1−p*)(z*ME)2

2020 Election ~ Bernie Sanders is a popular presidential candidate among university students for the 2020 presidential election. Leading into Michigan’s presidential primary election in 2020, a journalist, Lauren took a random sample of 11,590 university students and found that 8,066 of them support Bernie Sanders.

Using this data, Lauren wants to estimate the actual proportion of university students who support Bernie Sanders.

To calculate the required sample size, what value ofz*. should we use in the formula below to calculate a 90% confidence interval within 2.82 percentage points? Give your answer to 4 decimal places.

n=p*(1−p*)(z*ME)2

1. The time need to complete a final examination in a college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. a. What is the probability of completing the exam in less than 60 minutes? b. What is the probability of completing the exam in less than 95 minutes? c. What is the probability of completing the exam in more than 75 minutes? d. What is the probability of completing the exam within 60 to 75 minutes? e. 35% of students complete the exam in less than what time? f. 95% of students complete the exam in less than what time? g. 10% of students complete the exam in more than what time?

The Dean of a small college is investigating student preferences in class scheduling, and whether start times should be on the hour or the half-hour. She decides to survey a subgroup of the student body, consisting of 127 students (not everyone responded). Of this group 73 students supported starting on the hour, the remainder supported the half hour.

a. What is the 90% confidence interval on the proportion of students supporting classes on the hour?

b. Classes are currently on the half hour. Based on your analysis of the results, do you think the Dean should make a change?

c. If you repeated the analysis as a hypothesis test at 90% significance using a null hypothesis of p = 0.50, what would your result be?

In a study of government financial aid for college​ students, it becomes necessary to estimate the percentage of​ full-time college students who earn a​ bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.05 margin of error and use a confidence level of 99%. Complete parts​ (a) through​ (c) below.

1) Assume that nothing is known about the percentage to be estimated.

n=

2)Assume prior studies have shown that about 45%of​ full-time students earn​ bachelor's degrees in four years or less.

n=

3)Does the added knowledge in part​ (b) have much of an effect on the sample​ size?

More than 100 million people around the world are not getting enough sleep; the average adult needs between 7.5 and 8 hours of sleep per night. College students are particularly at risk of not getting enough shut-eye.

A recent survey of several thousand college students indicated that the total hours of sleep time per night, denoted by the random variable X, can be approximated by a normal model with E(X) = 6.74 hours and SD(X) = 1.18 hours.

Question 1. Find the probability that the hours of sleep per night for a random sample of 4 college students has a mean x between 6.82 and 6.96.