From generation to generation, the mean age when smokers first start to smoke varies. A survey of 20 smokers of this generation was done to see if the mean starting age was under 19 years old. The sample mean was 18.1 years old, with a sample standard deviation of 1.3 years. Is the data significant at =.05%?

a. State the null and alternative hypotheses

b. Find the SEM and then perform z-score and find p-value.

c. Perform Cohen's d equation

d. State answer