Math graph question need help asp

Which term best describes the association between variables a and b

What are the equivalent ratios for 24/2= /3= /5.5=108/ = /15

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?