A surgeon would like to know how long it takes, on average, to complete a coronary artery bypass surgery. She samples 29 surgeries and logs the time it takes to complete each one, in hours:

3.7, 5.3, 3.1, 3.8, 3.4, 3, 4.1, 3.4, 3.4, 3.8, 4.3, 5, 4.4, 4.9, 3.1, 4.7, 4.5, 4.1, 3.5, 5.2, 4.5, 3.9, 5.1, 4, 2.5, 4.6, 5.5, 3.8, 3.5

Assuming the population standard deviation is

=

0.85

=0.85

, construct a 90% confidence interval for the average time it takes to complete a coronary artery bypass surgery.

x

=

x=

2

=

2=

z

2

=

z2=

Margin of Error:E

=

E=

We are 90% confident that the mean amount of time it takes to complete a coronary bypass sugery is betweenhours andhours.