Let d = score in the last round - score in the first round and

Ha = mean in the last round - mean in the first round.

The population of paired differences of golf scores has normal distribution with unknown standard deviation. At 10% level of significance, test the claim that the professional golfers do better in the first round.

1. State the null and the alternative hypotheses.
2. Write down the formula of the test statistic and find its value.
3. Determine the rejection region and make a decision.
4. State a conclusion in the context of the problem.