Question

In: Statistics and Probability

Suppose we know that at a University XYZ that 15% of students receive an A in...

Suppose we know that at a University XYZ that 15% of students receive an A in their introductory statistics class, 20% receive a B, 30% receive a C, 10% receive a D, and the rest receive an F. For comparison, a sample of 260 students at University ABC is taken and 20% received an A, 25% received a B, 25% received a C, 10% received a D, and the remaining students failed the class. When testing (at the 5% level of significance) whether the proportions between the two universities are different, what is the critical value? (please round your answer to 3 decimal places)

Solutions

Expert Solution


Related Solutions

Suppose that at a large university 30% of students are involved in intramural sports. If we...
Suppose that at a large university 30% of students are involved in intramural sports. If we randomly select 12 students from this university, what is the probability that no more than 4 of these students are involved in intramural sports?
The university finance department wants to know if the average age of students at their university...
The university finance department wants to know if the average age of students at their university is greater than the average for other universities. A random sample of student records is taken from the own university (population 1) and a random selection of student ages from other three universities are taken (population 2). A significance level of 0.05 is chosen. The null and alternative hypotheses are: ?0: ??: The samples are selected, and the results are: ?1 = 28,7 ?????   ?1...
A university administrator expects that 25% of students in a core course will receive an A....
A university administrator expects that 25% of students in a core course will receive an A. He looks at the grades assigned to 60 students. a. What are the expected value and the standard error for the proportion of students that receive an A? b. Use an appropriate normal transformation to calculate the probability that the percentage of students that receive an A is 20% or less. c. Use an appropriate normal transformation to calculate the probability that the proportion...
Suppose we somehow know that for the entire population of all students, the mean time spent...
Suppose we somehow know that for the entire population of all students, the mean time spent exercising per week is 90 minutes, with a standard deviation of 40 minutes. a) Would you expect time spent exercising per week to be normally distributed? Explain your reasoning. Consider your exercise habits as well as those of people you know. b) We plan to collect random samples of 50 students and compute the sample mean time spent exercising, ?̅, for each sample. Would...
Suppose we somehow know that for the entire population of all students, the mean time spent...
Suppose we somehow know that for the entire population of all students, the mean time spent exercising per week is 90 minutes, with a standard deviation of 40 minutes. a) Would you expect time spent exercising per week to be normally distributed? Explain your reasoning. Consider your exercise habits as well as those of people you know. b) We plan to collect random samples of 50 students and compute the sample mean time spent exercising, ?̅, for each sample. Would...
A university dean is interested in determining the proportion of students who receive some sort of...
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 225 students and finds that 45 of them are receiving financial aid. Using a 95% confidence interval, what is the upper limit of the confidence interval to estimate the true proportion of students who receive financial aid.   Using a 95% confidence interval, what is the upper limit of the confidence...
Suppose that we know from a recent nationwide study that the average American watches 15 hours...
Suppose that we know from a recent nationwide study that the average American watches 15 hours of television per week with a population standard deviation of 4 hours. Assume that the distribution of the number of hours watched is normal.  Suppose that we randomly select 500 New Orleans residents and measure their average viewing hours are calculated as 24 hours. Use an appropriate statistical test to determine whether New Orleans residents differ from other Americans in terms of the number of...
A researcher wants to know the proportion of students at the university who live in residence....
A researcher wants to know the proportion of students at the university who live in residence. A sample of 50 students was taken and the researcher found 25 of them lived in residence. What is the 99% confidence interval for the proportion of students who live in residence?
In a university 20% students belong to the school of business (B), 15% to the school...
In a university 20% students belong to the school of business (B), 15% to the school of engineering(E) and 30% belong to the school of social sciences(S). Of the school of business students 35% have taken a statistics course, of the school of engineering students 45% have taken a statistics course, and of the school of social sciences students, 20% have taken a statistics course. Between the three schools, what fraction of students have taken a statistics course (Q)? If...
A local university wants to conduct a sample of 200 students out of 6000 students. We...
A local university wants to conduct a sample of 200 students out of 6000 students. We can assume that the university maintains a good roster of all registered students. (1) how would you select the 200 students(a) using simple random sample method and (b) systematic sampling method? (2) suppose that the university administration wants to make sure in particular students who major in music (a small department with only 8% of students major in music)be adequately included in your sample,...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT