Need help with this khan academy question. Plus minus square root of negative nine equals plus or minus

The number of hours per week that the television is turned on is determined for each family in a sample. the mean of the data is 37 hours and the median is 33.2 hours. twenty-four of the families in the sample turned on the television for 22 hours or less for the week. the 13th percentile of the data is 22 hours. approximately how many families are in the sample? round your answer to the nearest integer.

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

Point r divides in the ratio 1 : 5. if the coordinates of e and f are (4, 8) and (11, 4), respectively, what are the coordinates of r to two decimal places?