A random sample of mid-sized cars tested for fuel consumption gave a mean of miles per gallon with a standard deviation of miles per gallon.

Question

Assuming that the miles per gallon given by all mid-sized cars have a normal distribution, find a confidence interval for the population mean, .

Round your answers to two decimal places.

Answer 1

Use a confidence interval formula for the data.

Here is an example of one for a 95% confidence interval:

CI95 = mean ± 1.96 (sd/√n)