Ten sampled students of 18-21 years of age received special training. They are given an IQ test that is N (100, 102) in the general population. Let be the mean IQ of these students who received special training. The observed IQ scores: 121, 98, 95, 94, 102, 106, 112, 120, 108, 109

Test if the special training improves the IQ score using significance level = 0.05.

1. What is the rejection region?
2. Calculate the p-value and state your conclusion.
3. What if the variance is unknown?

Please include all r codes!