PLEASE HELP ASAP WHICH ARE PROPORTIONAL Marian earns $7.50 per hour at her part-time job. Is the number of hours Marian works proportional to the amount she earns?

The area of a square can be found by squaring the length of one of its sides. For example, if a square has a side length of 5 centimeters, the square's area is 5, 2, square centimeters, or 25 cm, 2, . Is the side length of a square proportional to its area?

Rafael opens a savings account with an initial deposit of $50. Each week after that, he deposits $10 more. Is the number of weeks that have passed proportional to the amount in his account?

Noah is mixing yellow and red paint. For every 5 ounces of yellow paint he adds 4 ounces of red paint. Is the number of ounces of yellow paint proportional to the number of ounces of red paint?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

Can someone me out here number 4 plz

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.