Rectangle QRST is shown. Angle QRT is congruent to angle STR, and angle STR is complementary to angle QTR. A rectangle has corner points Q, T, S, R from top left going clockwise. A line cuts through the rectangle from R to T. Which statement is true about angles QRT and QTR?

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”?