Crop researchers plant 15 plots with a new variety of corn T

Crop researchers plant 15 plots with a new variety of corn. The yields in bushels per acre are:

138.0 109.6

139.1 127.3

113.0 115.6

132.5 130.4

140.7 130.2

109.7 111.7

118.9 105.5

134.8

A) Find the 90% confidence interval for the mean yeild for this variety of corn.

B) Find the 95% confidence interval for the mean yeild for this variety of corn.

C) Find the 99% confidence interval for the mean yeild for this variety of corn.

D) How do the margins of error in (A), (B), and (C) change as the confidence level increases?

Please show all work and steps. Thank you!

a)
Confidence Interval
CI = x