Is this answer correct? (Division with fractions)

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”?

What is the y-intercept of the line with the equation 3x + 4y = 12?

Which of the following statements is a true conclusion that can be made from the scaled bargraph?