tate 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 standardized evaluation technique. The average score for the sample if M = 76. For the general population of college students, writing scores form a normal distribution with a mean of μ= 70. If the writing scores for a population have a standard deviation of σ = 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect? Assume a two-tailed test with α = .05.  If the population standard deviation is  = 10, is the sample sufficient to demonstrate a significant effect? Again, assume a two-tailed test with α = .05. Comparing your answers for parts a and b, explain how the magnitude of the standard deviation influences the outcome of a hypothesis test.

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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 standardized evaluation technique. The average score for the sample if M = 76. For the general population of college students, writing scores form a normal distribution with a mean of μ= 70.

  1. If the writing scores for a population have a standard deviation of σ = 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect? Assume a two-tailed test with α = .05. 
  2. If the population standard deviation is  = 10, is the sample sufficient to demonstrate a significant effect? Again, assume a two-tailed test with α = .05.
  3. Comparing your answers for parts a and b, explain how the magnitude of the standard deviation influences the outcome of a hypothesis test. 
  4.  





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