A study is conducted concerning the blood pressure of 60 year old women with glaucoma. In the study XXXXXXXXXXyear old women with glaucoma are randomly selected and the sample mean systolic blood...

A study is conducted concerning the blood pressure of 60 year old women with glaucoma. In the study 150 60-year old women with glaucoma are randomly selected and the sample mean systolic blood pressure is 135 mm Hg and the sample standard deviation is 25 mm Hg.
Calculate a 95% confidence interval for the true mean systolic blood pressure among the population of 60 year old women with glaucoma

Suppose the study above was based on 100 women instead of 200 but the sample mean (140) and standard deviation (25) are the same. Recalculate the 95% confidence interval. Does the interval get wider or narrower? Why