Which equation is a linear function?

Help please

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

Which statements about these triangles is true

What other information do you need to prove triangle dac=bca by asa