Im having trouble with these three questions

1. ) round $9.854 to the nearest dollar.

2.) round $56.9856 to the nearest cent.

3.) sierra is paid weekly salary of $550. how much does she earn in one year? (52 weeks in year)

The pyramid shown has a square base that is 24 centimeters on each side. the slant height is 16 centimeters. what is the lateral surface area?

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.

Adistribution has the five-number summary shown below. what is the third quartile, q3, of this distribution? 22, 34, 41, 55, 62