1. A high-school administrator who is concerned about the amount of sleep the students in his district are getting selects a random sample of 14 seniors in his district and asks them how many hours of sleep they get on a typical school night. He then uses school records to determine the most recent grade-point average (GPA) for each student. His data and a computer regression output are given below. (remember to do ALL parts).

Sleep (hrs) 9 8.5 9 7 7.5 6 7 8 5.5 6 8.5 6.5 8 8

GPA 3.8 3.3 3.5 3.6 3.4 3.3 3.2 3.2 3.2 3.4 3.6 3.1 3.4 3.7

(a) Do these data provide convincing evidence of a linear relationship between the hours of sleep students typically get and their academic performance, as measured by their GPA? Carry out a significance test at the α = 0.05 level. (10 points)

(b) Construct and interpret at 95% confidence interval for the slope of the regression of GPA on hours of sleep for seniors in this school district. (5 points)

(c) Can we conclude from these data that students’ GPA will improve if they get more sleep? Explain. (

Randomly selected students were given five seconds to estimate the value of a product of numbers with the results shown below.
Estimates from students given 1×2×3×4×5×6×7×8:

10000, 2040, 750, 4000, 42200, 6000, 1500, 5000, 500, 5000

Estimates from students given 8×7×6×5×4×3×2×1:

100000, 10000, 52836, 1200, 450, 100000, 200, 2050, 1500, 400

Use a 0.05 significance level to test the following claims:

Claim: the two populations have equal variances.

The test statistic is  
The larger critical value is  
The conclusion is
A. There is sufficient evidence to reject of the claim that the two populations have equal variances. (So, we can assume the variances are unequal.)
B. There is not sufficient evidence to reject the claim that the two populations have equal variances. (So, we can assume the variances are equal.)

Claim: the two populations have the same mean.

The test statistic is  
The positive critical value is  
The negative critical value is  
The conclusion is
A. There is not sufficient evidence to reject the claim that the two populations have the same mean.
B. There is sufficient evidence to reject the claim that the two populations have the same mean.

A clothes factory wants to produce school uniforms for high school students. To get an idea on the sizes of the clothes the factory collected data on the height of 30 high school students. The data are measured in centimeters and recorded in the following table.

1. What type of data is this? Explain
2. If the manager of the factory wants to create a histogram, how many classes she should use? Explain
3. What is the width of each class? Explain.
4. Create a histogram.
5. What shape does this histogram have?
6. f. What information the manager of the factory would get from this histogram?
7. Create an Ogive.
8. From the Ogive, show the percentage of students who are 170 centimeters or below.

17.

Refer to the scenario to answer the following questions.
A government worker surveys a number of households and comes up with the following information: there were a total of 90 people in the households, 10 of the people were children under 16, 10 of the people were retired but still capable of working, 35 people had full-time jobs, 5 had part-time jobs, 5 were stay-at-home parents, 5 were full-time students over the age of 16, 5 were disabled people who could not work, 10 people had no job but were looking for jobs, and there were 5 people who wanted a job but were not looking for a job.

According to the information in the survey, the unemployment rate is

19.

Due to the rising cost of a college education, a greater percentage of students have part-time jobs in comparison to past years. All else the same, this decrease in the number of full-time students can be expected to ________ the labor force participation rate and ________ the unemployment rate.

Critical Thinking Use the data set which shows student grades and the number of homework assignments missed. You can use the pivot table feature in excel to make a crosstabulation or contingency table as a first step. Choose the best statement below.

Grades and homework data, click here https://drive.google.com/file/d/1nDzzuY-pXeRqisc9sKpuKfXOMHXkBeLv/view?usp=sharing

A. Passing the class appears to be strongly and negatively related to the number of missed homeworks. The probability of not passing the class is fairly low for students that turn in all homework assignments, moderate for students that miss one assignment and quite large for students that miss more than two assignments.

B. There appears to be only a weak relationship between the number of missed assignments and the grades.

C. Missing a homework assignment is a strong predictor of not getting an exceeds expectations grade (A or B). For student that miss one homework assignment the probability of getting an A or B is extremely small.

D. The conditional probability of missing at least one homework assignment given that a student got a C suggests that it is more likely than not that a student with a C missed at least one assignment and this is an indicator that missing a homework assignment or more increases a student's probability of getting a C.

Consider a multiple-choice examination with 50 questions. Each question has four possible answers. Assume that a student who has done the homework and attended lectures has a 75% probability of answering any question correctly. A student must answer 43 or more questions correctly to obtain a grade of A. What percentage of the students who have done their homework and attended lectures will obtain a grade of A on this multiple-choice examination? A student who answers 35 to 39 questions correctly will receive a grade of C. What percentage of students who have done their homework and attended lectures will obtain a grade of C on this multiple-choice examination? A student must answer 30 or more questions correctly to pass the examination. What percentage of the students who have done their homework and attended lectures will pass the examination? Assume that a student has not attended class and has not done the homework for the course. Furthermore, assume that the student will simply guess at the answer to each question. What is the probability that this student will answer 30 or more questions correctly and pass the examination?

Is there a way to see this problem worked in Excel using the STDEV.S function? Would this be a one-tailed test or a two tailed test?

#4
**Below are two samples of test scores from two different calculus classes. It is believed that class 1 performed better than class two. From previous tests, it is known that the test scores for both classes are normally distributed and the population standard deviation of class 1 is 10 points and the population standard deviation of class 2 is 8 points. Do the data support that class 1 performed better.**
```{r}
class1<-c(100, 86, 98, 72, 66, 95, 93, 82)
class2<-c(98, 82, 99, 99, 70, 71, 94, 79)

```

##5
**A teaching assistant in Florida collected a sample to see if the average number of hours students put into studying depending on if they were in graduate school or not. The data below represents these two samples.**

**Perform a test to determine if the time graduate students spend studying is greater than that of undergraduate students. Be sure to identify your hypotheses and explain your conclusion in the context of the question. Assume the time spend studying for both graduate and undergraduate is normally distributed.**

grad<-c(15,7,15,10,5,5,2,3,12,16,15,37,8,14,10,18,3,25,15,5,5)
undergrad<-c(6,8,15,6,5,14,10,10,12,5)

Please Solve using R studio codes with explanation

A teacher instituted a new reading program at school. After 10 weeks in the​ program, it was found that the mean reading speed of a random sample of 20 second grade students was

94.4 wpm. What might you conclude based on this​ result? Select the correct choice below and fill in the answer boxes within your choice.

​(Type integers or decimals rounded to four decimal places as​ needed.)

A. A mean reading rate of 94.4 wpm is not unusual since the probability of obtaining a result of 94.4 wpm or more is ____. This means that we would expect a mean reading rate of 94.4

or higher from a population whose mean reading rate is 92 in ____ of every 100 random samples of size n=20 students. The new program is not abundantly more effective than the old program.

B. A mean reading rate of 94.4 wpm is unusual since the probability of obtaining a result of 94.4 wpm or more is ____. This means that we would expect a mean reading rate of 94.4

or higher from a population whose mean reading rate is 92 in ____ of every 100 random samples of size n=20 students. The new program is abundantly more effective than the old program.

During the last couple of decades, colleges and universities have tried to increase their number of minority students by various forms of affirmative action. At Campus X, this has led to no small amount of dissension. Some students complain that the policy of accepting students with lower SAT and other scores just because of their race or minority status is unfair. Others believe that the diversity that results from such policies is good for everyone because we should learn to live together and a university campus should be a place to do this. Still, there is some question, even among members of this group, as to how well the integration is working. Furthermore, a different type of problem has recently surfaced. Because Asian Americans were represented in numbers grater than their percentage of the population, some universities were restricting the percentage of the population they would accept even when their scores were higher than others they did accept. Also, in some cases where affirmative action has been eliminated, the number of minority members accepted into certain medical and law schools has plummeted, and many people find this alarming.

Do you think that diversity ought to be a goal of campus admissions?

Or do you believe that only academic qualifications ought to count? Why?

Let us say that the SBRU information system includes four subsystems: Resort relations, Student booking, Accounting and finance, and Social networking. The first three are purely Web applications, so access to those will be through an Internet connection to a Web server at the SBRU home office. The Social networking subsystem has built-in chat capabilities. It relies on Internet access for the students, as students compare notes before they book their travel reservations and as they chat while traveling. To function properly, the system obviously requires a wireless network at each resort during the trip. SBRU isn’t responsible for installing or maintaining the resort wireless network; they only plan to provide some design specifications and guidelines to each resort. The resort will be responsible for connecting to the Internet and for providing a secure wireless environment for the students.

1. Design the environment for the SBRU information system by drawing a network diagram. Include what might be necessary to support online chatting capabilities.

2. Considering that everything is designed to operate through the Internet with browsers or smart phones, how simple does this architecture appear to be? Can you see why Web and smart phone applications are so appealing?

3. What aspect of design becomes extremely important to protect the integrity of the system?