A professor at a community college claims that a college algebra student can increase his or her score on an exam if the person is provided with a pre-test the week before the exam. To test her theory, she selected 16 college algebra students at random and gave these students a pre-test the week before an exam. She also selected a random sample of 12 students who were given the same exam but did not have access to a pre-test. The first group had a mean score of 79.4 with standard deviation 8.8. The second group had a mean score of 71.2 with standard deviation 7.9. Test to see if the population mean score of students who get a pre-test is different from the population mean score of those who do not. Use a 5% significance level. a. Would you use the normal distribution (z) or Student's (t) distribution? Why?b. State the test statistic and p-value of your test. Round your answers to four decimal places.c. Explain your decision to reject or fail to reject the null hypothesis in terms of p and α.d. Interpret your conclusion in the context of this problem.

We have given that Sample sizes n1= 16 , n2= 12 The first group had a mean score of 79.4 with…

Answered: A professor at a community college…

Holt Mcdougal Larson Pre-algebra: Student Edition 2012

1st Edition

ISBN:9780547587776

Author:HOLT MCDOUGAL

Publisher:HOLT MCDOUGAL

Chapter11: Data Analysis And Probability

Section: Chapter Questions

Problem 8CR

See similar textbooks

Related questions

Question

A professor at a community college claims that a college algebra student can increase his or her score on an exam if the person is provided with a pre-test the week before the exam. To test her theory, she selected 16 college algebra students at random and gave these students a pre-test the week before an exam. She also selected a random sample of 12 students who were given the same exam but did not have access to a pre-test. The first group had a mean score of 79.4 with standard deviation 8.8. The second group had a mean score of 71.2 with standard deviation 7.9. Test to see if the population mean score of students who get a pre-test is different from the population mean score of those who do not. Use a 5% significance level.

a. Would you use the normal distribution (z) or Student's (t) distribution? Why?

b. State the test statistic and p-value of your test. Round your answers to four decimal places.

c. Explain your decision to reject or fail to reject the null hypothesis in terms of p and α.

d. Interpret your conclusion in the context of this problem.

Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.

Expert Solution