In a sample of seven cars, each car is tested for nitrogen oxide emissions (in grams per mile) and the following results

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In a sample of seven cars, each car is tested for nitrogen oxide
emissions (in grams per mile) and the following results are
obtained: 0.06, 0.11, 0.16, 0.15, 0.14, 0.08, 0.15 (based on data
from the Environmental Protection Agency). Assume that this sample
is representative of cars in use and has a normal distribution.
a) Construct a 95% confidence interval estimate for the mean
amount of nitrogen oxide emissions for all cars.
b) If the Environmental Protection Agency requires that nitrogen
oxide emissions be less than 0.165 g/mi. Can we safely conclude
that this requirement is met?
Give Excel equations as well as all procedure.