Which segment is a median for the triangle abc

Thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 127 millimeters, and a variance of 36. if a random sample of 35 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by greater than 0.5 millimeters? round your answer to four decimal places.

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Someone which statements are true? check all that apply.