Please show your work, I'm really confused about T critical value

A researcher wishes to estimate the average blood alcohol concentration(BAC) for drivers involved in fatal accidents who are found to have positive BAC values. He randomly selects records from 60 such drivers in 2009 and determines the sample mean BAC to be 0.17 g/dL with a standard deviation of 0.070 g/dL.

c) Determine and interpret a90% confidence interval for the mean BAC in fatal crashes in which the driver had a positive BAC.

(Use ascending order. Round to three decimal places asneeded.)

A.

The lower bound is ......and the upper bound is .....The researcher is10% confident that the population mean BAC is in the confidence interval for drivers involved in fatal accidents who have a positive BAC value.

B.

The lower bound is .... and the upper bound is ......The researcher is90% confident that the population mean BAC is in the confidence interval for drivers involved in fatal accidents who have a positive BAC value.

C.

The lower bound is ......and the upper bound is ......The researcher is90% confident that the population mean BAC is not in the confidence interval for drivers involved in fatal accidents who have a positive BAC value.