Set up null and alternative hypothesis to test various claims. Example: Nike sells you a golf ball that it claims will add 20 yards to your shot.

Set up null and alternative hypothesis to test various claims.
Example: Nike sells you a golf ball that it claims will add 20 yards to your
shot. To test this claim, you hit the new Nike ball 50 times and average
210 yards over the sample with a standard deviation of 100.
Furthermore, you hit your old golf ball 50 times and average 198 yards
with a standard deviation of 150. Is this enough evidence to conclude
that the new balls improve your distance at least some? Is this enough
evidence to confirm or deny that the new balls add at least 20 yards?
1. Compute test statistics, which are simply standardized values of the sample
mean under the null hypothesis. (The formula will be in the exam: subtract the
hypothesized mean and divide by the standard error.)
2. Use a test statistic to look up a p-value in a z-table.
3.Interpret the results and conclude.