Suppose a consultant claims a training course will increase typing speed by at least 10 words per minute. A manager enrolls 15 employees and notes an increase of only 7 words per minute with a standard deviation 2.5.

1. What are the appropriate null and alternative hypotheses? Explain.
2. Is this a right, left, or 2 tailed test? Explain.
3. What is the rule for rejecting a null hypothesis based on a t statistic?
4. For what values of the t statistic will you reject the null hypothesis at a 5% significance level?
5. Find the test statistic and interpret the result of the test.
6. What is a Type 1 error?
7. What is a Type 2 error?
8. Explain the difference between Type I and Type II errors in this context.