The following histogram represents the distribution of acceptance rates (percent accepted) among 25 business schools in 2004. In each class interval, the left endpoint but not the right is included, so the class intervals are [10, 15), {15, 20) etc. What percentage of universities had acceptance rates less than 25%?

The following data have been collected from 500 students on whether they are Male or Female, and whether they have a car or not: Have a car Don’t have a car Total Male 125 25 150 Female 200 150 350 Total 325 175 500 If a randomly selected student have a car, what is the probability that the student is a male?   

Please note that this question consists of four parts. You may use MINITAB to double check your final answer. However you MUST show all the mathematical work to get to the final answer. Just giving the answer without adequate work/explanation may result in zero for the question.   A study was conducted to determine the percentage of adults in United States who are afraid to fly. Of the 1075 adults in United States surveyed, 292 were afraid to fly. Give a point estimate for the true proportion of adults in United States who are afraid to fly. The study wants to release an interval estimate for the true proportion of adults in United States who are afraid to fly. What are the conditions that need to be satisfied in order to calculate a confidence interval? Are they satisfied?  Calculate a 95% confidence interval for the true proportion of adults in United States who are afraid to fly. Interpret the interval calculated in part 3. 

A nutritionist wants to see whether a new diet will help reduce weight for women. He randomly selects 15 women and assigns them to the new diet program (length of the program is one month). For each woman, he records their weights as they start the diet and after they complete the diet program. To test whether mean reduction in weight is significant, we would do:

The average age of residents in a large residential retirement community is 69 years with standard deviation 5.8 years. A simple random sample of 100 residents is to be selected, and the sample mean age

Student body leaders at a college want to conduct a survey to determine the proportion of students who favor a proposed honor code. Since interviewing all the students is not feasible due to practical reasons, they want to determine the sample size (number of students to be interviewed) needed to estimate the true proportion with a margin of error no larger than 5% using a 95% confidence interval. What is the sample size they need to ensure above specifications in their estimation?  

Let A and B be events such that  Then P( A and B) is given by:

For each of the below statements, state if it is true or false. 

Please note that this question consists of five parts. Show all your work. Just giving the answer without showing work may result in zero for the question.  Data from a simple random sample of 121 Penn State seniors were collected. As a part of the study, they were asked below two questions: What is your current GPA? Are you planning on applying to graduate school? For the sampled 121 students, the average GPA is 3.6 and the standard deviation is 0.36. Find a 95% confidence interval for the average GPA of Penn State seniors.   A recent study claims that the average undergraduate GPA in U.S. universities is about 3.4. Based on your calculation in part 1, are Penn State seniors doing better in terms of their GPA? In the sample of 121 students, 18 said they plan on applying to graduate school. Find a 95% confidence interval for the proportion of Penn State seniors who plan on going to graduate school.  What conditions need to be satisfied in order for you to calculate the confidence interval in part 3? Are they satisfied? Rather than constructing a confidence interval, I decided to carryout the below hypothesis test.  Formulated hypothesis is:

Students in an introductory statistics class participate in a mid-semester survey. They were asked whether having quizzes better prepare them for the midterms. Their opinion of quizzes were coded as “0” if the answer is No, “1” if the answer is somewhat helpful, “2” if the answer is yes. This variable is: