State college is evaluating a new english composition course for freshmen. A random sample of N=25 freshmen is obtained and the students are placed in the course during their first semester. One year later, a writing sample is obtained for each student and the writing samples are graded using a standard evaluation technique. The average score for the sample is m=76. For the general population of college students, writing scores form a normal distribution of m = 70.
A. If the writing scores for the population have a standard deviation of 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect? Assume a two tailed test with alpha level of 0.05.
B. If the population standard deviation is 10 , is the sample sufficient to demonstrate a significant effect? Again assume a two tailed test with alpha level of 0.05.
C. comparing your answer for parts a and b explain how the magnitude of the standard deviation influences the outcome of a hypothesis test.© BrainMass Inc. brainmass.com September 18, 2018, 11:07 pm ad1c9bdddf - https://brainmass.com/statistics/hypothesis-testing/statistics-college-writing-scores-507069
Null Hypothesis: The new composition course does not have a significant effect.
Ho: u = 70.
Alternate Hypothesis: The new composition course has a significant effect.
H1: u does not equal 70.