Please help i’ll give u a brainliest for the correct answer

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Write the rational number in lowest terms 99/-15

Question 1 of 10 2 points different groups of 50 graduates of an engineering school were asked the starting annual salary for their first engineering job after graduation, and the sampling variability was low. if the average salary of one of the groups was $65,000, which of these is least likely to be the average salary of another of the groups? o a. $64,000 o b. $65,000 o c. $67,000 o d. $54,000