The weights, in pounds, of dogs in a city are normally distributed with a population standard deviation of2

pounds and an unknown population mean. A random sample of16

dogs is taken and results in a sample mean of28

pounds.

Identify the parameters needed to calculatea confidence interval at the90%

confidence level. Then find the confidence interval.

z

0.10

z

0.10

z

0.05

z

0.05

z

0.025

z

0.025

z

0.01

z

0.01

z

0.005

z

0.005

1.282

1.645

1.960

2.326

2.576

You may use a calculator or the commonz

values above.

• Round the final answer to twodecimal places.