An agricultural researcher is interested in estimating the mean length of the growing season in a region. Treating the last 10 years as a simple random sample, he obtains the following data, which represent the number of days of the growing season.

160 157 146 139 171 186 189 175 164 149

Because the sample size is small, we must verify that the data come from a population that is normally distributed and that the sample size does not contain any outliers. The normal probability plot and boxplot are shown below.

A. Are the conditions for constructing a confidence interval about the mean satisfied?

A.Yes, both conditions are met.

B.No, there are outliers.

C.No, neither condition is met.

D.No, the population is not normal.

B. b) Construct a 95% confidence interval for the mean length of the growing season in the region.(Use ascending order. Round to two decimal places as needed.)

(c) What can be done to decrease the margin of error, assuming the researcher does not have access to more data?

A.The researcher could increase the level of confidence.

B.The researcher could decrease the level of confidence.

C.The researcher could decrease the sample standard deviation.

D.The researcher could increase the sample mean.