Which two quantities form a proportional relationship?
a.1/4 and 3/8
b.2/15 and 3/30
c.10/18 and 45/81
d.5/6 and 5/24

Can someone with this one pre-calc question? the finishing time for a runner completing the 200-meter dash is affected by the tail-wind speed, s. the change, t, in a runner's performance is modeled by the function shown below: t= 0.0119s^2 - 0.308s - 0.0003 predict the change in a runner's finishing time with a wind speed of 3 meters/second. note: a negative answer means the runner finishes with a lower time. round to the nearest hundredth.

The head librarian at the library of congress has asked her assistant for an interval estimate of the mean number of books checked out each day. the assistant provides the following interval estimate: from 740 to 920 books per day. what is an efficient, unbiased point estimate of the number of books checked out each day at the library of congress?

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?