An instructor believes that students do not retain as much information from a lecture on a Friday compared to a Monday. To test this belief, the instructor teaches a small sample of college students some preselected material from a single topic on statistics on a Friday and on a Monday. All students received a test on the material. The differences in exam scores for material taught on Friday minus Monday are listed in the following table. Difference Scores (Friday − Monday) +4.4 +3.3 −1.6 +1.1 +6.2 (a) Find the confidence limits at a 95% CI for these related samples. (Round your answers to two decimal places.) to (b) Can we conclude that students retained more of the material taught in the Friday class? Yes, because 0 lies outside of the 95% CI. No, because 0 is contained within the 95% CI.

1. In a survey of 700 community college students, 481 indicated that they have read a book for personal enjoyment during the school year (based on data from the Community College Survey of Student Engagement).
   1. Determine a 90% confidence interval for the proportion of community college students who have read a book for personal enjoyment during the school year. You must show your work. Round the limits to the nearest thousandth.
2. 2. For a 90% confidence interval, would it be unusual if less than 450 students indicated that they have read a book for personal enjoyment during the school year? Justify your answer.
3. 3. For a 99% confidence interval, would it be unusual if less than 450 students indicated that they have read a book for personal enjoyment during the school year? Justify your answer.

You are interested in finding a 98% confidence interval for the average number of days of class that college students miss each year. The data below show the number of missed days for 10 randomly selected college students.

a. To compute the confidence interval use a

distribution.

b. With 98% confidence the population meannumber of days of class that college students miss is between and days.

c. If many groups of 10 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population mean number of missed class days and about percent will not contain the true population mean number of missed class days.

For any Hypothesis Test make sure to state Ho, Ha, Test statistic, p-value, whether you reject Ho, and your conclusion in the words of the claim. For any confidence interval make sure that you interpret the interval in context, in addition to using it for inference.

Round to the thousandths place

A survey is given to 300 random SCSU students to determine their opinion of being a “Tobacco Free Campus.” Of the 300 students surveyed, 228 were in favor a tobacco free campus.

1. Find a 95% confidence interval for the proportion of all SCSU students in favor of a tobacco free campus.
2. Interpret the interval in part a.
3. Find the error bound of the interval in part a.
4. The Dean claims that at least 70% of all students are in favor of a tobacco free campus. Can you support the Dean’s claim at the 95% confidence level? Justify!

23A. A health psychologist is interested in whether certain situations produce different amounts of stress. A group of 15 students is randomly assigned to one of three groups. The students in group 1 have their stress levels measured immediately after returning from vacation. The students in group 2 have their stress levels measured after they have been in class for a week. The students in group 3 have their stress levels measured immediately before final exams week. Use this information to complete the ANOVA table provided below.

23B. Using the ANOVA table above, calculate the least biased measure of effect size.

23C. Interpret (in words) the magnitude of effect you computed above.

In the Fall semester, 112 students attended a 5-day field trip to Washington DC. During the trip, 43 of the students became ill with norovirus, a highly contagious gastrointestinal illness that is shed in the feces of infected persons. All of the students who attended the field trip live in the same dormitory, which houses a total of 438 residents. In the week following the return of the travelers, another 168 dormitory residents became ill with norovirus. Over the course of the primary and secondary outbreaks, 2 students died as a result of complications from norovirus infection.

Question: What is the Secondary Attack Rate (SAR) of norovirus in this outbreak?

* I am having trouble understanding if you should subtract the pre existing cases from the total exposed denominator I just need some clarification thank you

Exam Grades

Exam grades across all sections of introductory statistics at a large university are approximately normally distributed with a mean of 72 and a standard deviation of 11. Use the normal distribution to answer the following questions.

(a) What percent of students scored above a 90 ?

Round your answer to one decimal place.

(b) What percent of students scored below a 58 ?

Round your answer to one decimal place.

(c) If the lowest4%of students will be required to attend peer tutoring sessions, what grade is the cutoff for being required to attend these sessions?

Round your answer to one decimal place.

Cutoff grade =

(d) If the highest11%of students will be given a grade of A, what is the cutoff to get an A?

Round your answer to one decimal place.

Cutoff grade =

Exercise 3

The data in the table represent the "Exam Scores" for two random samples of students. The first group of = 6 students were under active-learning course, and the second group of = 6 students were under traditional lecturing. Note that the standard deviations in the Active group is = 3.43 and in the Traditional group is = 3.03.

Please answer the following questions underneath each question.

1. Which test is appropriate to compare the Exam-Scores in the two groups of students?

Answer:

2. Conduct the steps of this test

(please enumerate and write all the steps of your answer below)

Step 1:

3. State your conclusion in the context of this study

I have collected about 200 samples worth of data to determine whether students that are not full time, full time being defined as anyone with 12 or more units, have a higher GPA than students who are full time. For this case our variances are not equal to each other and our samples are independent of each other.

How would you set up the hypothesis test for this case?

I originally have it set up like this but not sure if it is correct.

Students who are not full time are denoted as M₁ and Student who are full time are denoted as M₂

Ho : M₁ - M₂ = 0 *This means that students who not full time have a higher GPA*

H₁ : M₁ - M₂ > 0 *This means that student who are full time have a higher GPA*

Consider the variable x = time required for a college student to complete a standardized exam. Suppose that for the population of students at a particular university, the distribution of x is well approximated by a normal curve with mean 55 minutes and standard deviation 5 minutes. (Use a table or technology.)

(a)

If 60 minutes is allowed for the exam, what proportion of students at this university would be unable to finish in the allotted time? (Round your answer to four decimal places.)

(b)

How much time (in minutes) should be allowed for the exam if you wanted 95% of the students taking the test to be able to finish in the allotted time? (Round your answer to one decimal place.)

min

(c)

How much time (in minutes) is required for the fastest 20% of all students to complete the exam? (Round your answer to one decimal place.)

min