Chelsea wants to buy a new iPhone that costs $324. She has already saved $56. If she can save $20 a week, how
many weeks will it take for her to be able to purchase the
iPhone?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

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.

Which one is the correct answer, and why?