11. A relative frequency value of 0.074 is equal to what percentage?

12. What is incorrect in the grouped frequency classes below?

Class Interval

100 - 105

105 - 110

110 - 115

115 - 120

A. There are no problems

B. The classes are not mutually exclusive

C. The class width is inconsistent

D. The classes are not continuous

12. The possible grades on a statistics class project are A, B, C, D, and F. In one section, the frequency of Cs in the class is 10. Which of the following statements are true?

14. The midpoint for the class 83 - 87 is _____.

15. What is incorrect in the grouped frequency classes below?

Class Interval

27 - 32

33 - 38

40 - 45

46 - 51

52 - 57

16. The class width for the class intervals below is ________.

83 - 87

88 - 92

93 - 97

1. Ramilda wants to see if other students in her class listen to podcasts for a longer amount of time than students across the country. She collects data from twenty students in her class concerning the number of minutes per day they listen to podcasts. On average people in the United States listen to podcasts for 93 minutes per day. The data from her participants are summarized below:

1. What are the null and alternative hypotheses using mathematical notation (1 point)?

2. Compute the appropriate test statistic for testing the hypothesis (5 points).

3. Using  = .05, what do you conclude about how Remilda’s class compares to other students across the country in the amount of time they spend listening to podcasts? Be sure to provide the critical value in your answer (1.5 points).

Q4. In a survey of

3272

adults aged 57 through 85​ years, it was found that

81.1​%

of them used at least one prescription medication.

b. Construct a​ 90% confidence interval estimate of the percentage of adults aged 57 through 85 years who use at least one prescription medication.

nothing​%less than<pless than<nothing​%

​(Round to one decimal place as​ needed.)

What do the results tell us about the proportion of college students who use at least one prescription​ medication?

A.The results tell us​ that, with​ 90% confidence, the probability that a college student uses at least one prescription medication is in the interval found in part​ (b).

B.The results tell us that there is a​ 90% probability that the true proportion of college students who use at least one prescription medication is in the interval found in part​ (b).

C.The results tell us​ that, with​ 90% confidence, the true proportion of college students who use at least one prescription medication is in the interval found in part​ (b).

D.The results tell us nothing about the proportion of college students who use at least one prescription medication.

Two professors at a local college developed a new teaching curriculum designed to increase​ students' grades in math classes. In a typical developmental math​ course, 53​% of the students complete the course with a letter grade of​ A, B, or C. In the experimental​ course, of the 14 students​ enrolled, 11 completed the course with a letter grade of​ A, B, or C. Is the experimental course effective at the alpha equals 0.01 level of​ significance? Complete parts ​(a) through​ (g).

​(a) State the appropriate null and alternative hypotheses.

​(b) Verify that the normal model may not be used to estimate the​ P-value.

​(c) Explain why this is a binomial experiment

(d) Determine the​ P-value using the binomial probability distribution. State your conclusion to the hypothesis test.

​(e) Suppose the course is taught with 4242 students and 3333 complete the course with a letter grade of​ A, B, or C. Verify whether the normal model may now be used to estimate the​ P-value

(f) Use the normal model to obtain and interpret the​ P-value. State your conclusion to the hypothesis test.

(g) Explain the role that sample size plays in the ability to reject statements in the null hypothesis.

Stat212 Statistical II B Spring 2020 Midterm 2 Name:

SHOW YOUR WORK TO EARN FULL CREDIT

1. (20 points) Susan Sound predicts that students will learn most effectively with a constant background sound, as opposed to an unpredictable sound. She randomly divides 15 students into 2 groups of 7 and 8 each. All students study a passage of text for 30 minutes. Those in group 1 study with background sound at a constant volume in the background. Those in group 2 study with noise that changes volume periodically. After studying, all students take a 10 point multiple choice test over the material. Their scores have the following test statistics.

Group Constant sound Random sound

Sample size Mean Variance

8 6 4.86
7 4 2.86

1. Construct the F statistic ANOVA table using data. Stat the hypotheses for ANIVA and use significance level 0.05 to test your hypotheses. What is the p-value of the test?

2. Explain whether you use can conclusion above to support Susan’s prediction or not? Explain why and how.

Dr. Palpatine teaches statistics at Coruscant University. He believes there are three types of classes he may encounter:

(P) Poor classes, where only 70% of the students will be able to pass exam 1 in the course.

(A) Average classes, where 85% of the students will be able to pass exam 1.

(G) Good classes, where 95% of the students will be able to pass exam 1.

Assuming Palpatine teaches a class of 35 students...

If the class is poor (P), what is the probability that exactly 30 of them will pass (E), that is what is P(E|P)? _______

If the class is average (A), what is the probability that exactly 30 of them will pass (E), that is what is P(E|A)? _______

If the class is average (G), what is the probability that exactly 30 of them will pass (E), that is what is P(E|G)? _______

Now suppose that Palpatine initially believed the probability that his class was poor, average, and good was 25%, 50%, and 25% respectively. Use Bayes' Rule and the results above to find P(G|E), the probability his class is a good one (G) given the evidence E that exactly 30 of them passed the first exam. ______

The College Board provided comparisons of Scholastic Aptitude Test (SAT) scores based on the highest level of education attained by the test taker's parents. A research hypothesis was that students whose parents had attained a higher level of education would on average score higher on the SAT. The overall mean SAT math score was 514.† SAT math scores for independent samples of students follow. The first sample shows the SAT math test scores for students whose parents are college graduates with a bachelor's degree. The second sample shows the SAT math test scores for students whose parents are high school graduates but do not have a college degree.

c) find the value of the test statistic. (round your answer to three decimal places)

d) compute the p-value for the hypothesis test ( round your answer to four decimal places) p value=

At a local business school, it is typical for some fraction of students to pass an Accounting certification exam. Recently, funding was used to develop a new program that was designed to increase the proportion of students who pass the exam. The school that developed this program studied 475 students and found that the percentage of students who passed the certification increased to 72% with a 95% confidence interval of [.68, .76]. The hypothesis test, H0: No improvement / same rate as always vs. H1: The intervention changed the passing rate, was rejected with a p-value of .046.  

1. Explain what the​ p-value means in this context.

   1. Someone says that they thought that the original pass rate was 67%. If that were true, what would you tell them about the efficacy of the program? Phrase the conclusion properly.

   2. If the alternative hypothesis had been, H1: The intervention increased the passing rate, would the p-value change? If so, how? Would you more or less strongly recommend adoption of the new program?   

   3. Even though this program has been shown to be better​ in that it is “statistically significant”, are there reasons that the school should not adopt it?

   4. What is the relationship between the p-value and the confidence interval?   

Design a program which uses functions to sort a list and perform a binary search. Your program should:

Iinitialize an unsorted list (using the list provided)

Display the unsorted list

Sort the list

Display the sorted list.

Set up a loop to ask the user for a name, perform a binary search, and then report if the name is in the list. Use a sentinel value to end the loop.

Do not use the Python built in sort function to sort the list, instead write one or more functions to implement either the bubble sort or insertion sort (you choose the one you want to implement). The algorithms for the bubble sort and insertion sort are provided in the Word document attachment.

Implement the binary search algorithm as a function. Algorithms are provided in the Word document attachment for an iterative version or recursive version of the binary search. You choose the one you want to implement.

Use this test list: [ 'Paul', 'Aaron', 'Jacob', 'James', 'Bill', 'Sara', 'Cathy', 'Barbara', 'Amy', 'Jill' ]

Turn in your source code with IPO comments at the top of the file

A screen shot showing the results of your testing.