CarMD reports that the mean repair cost of a Toyota in 2018 for a "check engine" light was $482.
Suppose a sample of 100 "check engine" light repairs completed in the last month was selected. The sample mean repair cost was $271 with the sample standard deviation of $ 100.
a. Is there evidence that the population mean repair cost is less than $482? (Use a 0.05 level of significance.)
b. Determine the p-value and interpret its meaning.