Answer
margin of error = 0.016 and sample mean = 3.16
Work Step by Step
Find the width of the interval
3.176 - 3.144 = 0.032
Find the margin of error by dividing the interval width by two:
0.032/2 = 0.016
Subtract the margin of error from upper bound to find mean
3.176 - 0.016 = 3.16
Therefore, margin of error = 0.016 and sample mean = 3.16