A perfect square is the product of any positive whole number used as a factor exactly two times. [Example: 49 is a perfect square because 7 × 7 = 49] … The positive whole number N, when multiplied by 150, is a perfect square.

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”?