in a random sample of six microwave ovens, the mean repair cost was $70.00 and the standard deviation was $12.

in a random sample of six microwave ovens, the mean repair cost was $70.00 and the standard deviation was $12.50. Assume the population is normally distributed and use a t-distribution to construct a 90% confidence level for the population mean.

a) 90%=

b) what is the margin of error?

c) interpret the results?