Answer
There is sufficient evidence to support that the mean age of race car drivers is more than 30 years.
Work Step by Step
$H_{0}:\mu=30$. $H_{a}:\mu > 30.$ Hence the value of the test statistic: $\frac{\overline{x}-\mu}{s/\sqrt n}=\frac{33.6-30}{7.67/\sqrt{16}}=1.818.$ The P-value is the interval of probabilities between which the value of the test-statistic lies in the table with degree of freedom=sample size-1=15-1=14, hence P is between 0.025 and 0.05. If the P-value is less than $\alpha$, which is the significance level, then this means the rejection of the null hypothesis. Hence:P is less than $\alpha=0.05$, hence we reject the null hypothesis. Hence we can say that there is sufficient evidence to support that the mean age of race car drivers is more than 30 years.
