15

A statistics teacher wants to see if there is any difference in the abilities of students enrolled in statistics today (2016)and those enrolled five years ago (2011). A sample of final examination scores from students enrolled today and from students enrolled five years ago was taken. You are given the following information:

20162011

the sample mean score (xbar)8882

the population variance (sigma squared)54112.5

the sample size(n)3645

Fill inMultiple Blanks:

The point estimate for the difference between the means of the two populations (that is, mu 2016 - mu 2011) is_______In your answer,showone (1) digitto the right of the decimal point, for example, 1.0, 1.2. Apply the appropriate rounding rule if necessary.

The standard error of (xbar2016 -xbar2011) is________

In your answer, showone (1) digitto the right of the decimal point, for example, 1.0, 1.2. Apply the appropriate rounding rule if necessary.

The 95% confidence interval for the difference between the two population means is fromto________

In your answer,showone (1) digitto the right of the decimal point, for example, 1.0, 1.2. Apply the appropriate rounding rule if necessary.

The statistics teacher wants to test the following set of hypotheses:

Ho: mu 2016 - mu 2011 = 0

Ha: mu 2016 - mu 2011/= 0.

The actual value of the test statisticfor the difference between the two population means is_______

In your answer,showone (1) digitto the right of the decimal point, for example, 1.0, 1.2. Apply the appropriate rounding rule if necessary.

Since the actual value of the test statistic is(greater, less) than the critical value of the test statistic, the teacher(rejects, does not reject) the null hypothesis

and concludes that there(is, is no) statistically significant difference in the average final examination scores between the class of 2016 and the class of 2011.