The Manager of YoursTruly Agency decides to see whether a series of professional development seminars improves on work days per year. Some randomly selected employees take the seminars. Another sample of randomly selected employees without training are part of the control group.One year after the seminars, the figures shown in the accompanying table are available:

	SeminarGroup Days Worked	No SeminarGroup Days Worked
Mean	260	250
Standard Deviation	20	25
Sample Size (n)	16	25

A: State your null and alternative hypotheses

B: Using data from the question above, calculate your t-score - which involves first calculating the standard of error for the difference, s.e. D (calculate the standard error for each sample, square each, and then take the square root of their sum).Then dividethe difference in means by this value s.e. D (see formulas in your text; assume independent, unequal variance.)

C: Estimate the p-value for your t-score (using the simplified formula for degrees of freedom k equal to n₁+n₂-2, where n are the sample sizes.) You may use the Excel function=tdist(t, d.f., 1 tail)

D: Is the difference of means statistically different from zero? Is it practically different from zero? In other words, what can you tell the manager about this experiment? Should s/he institute the newtraining procedure? Does the sample size matter in your advice (would it be different if the samples were 50 each)?