Can someone help me on this plsss

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”?

Rectangle abcd is similar to rectangle rstu . what is the scale factor of a dilation from abcd to rstu ? enter your answer in the box.

Line ab contains points a(4, 5) and b(9.7). what is the slope of ab?