Pleas answer with work i really appreciate it thank you

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

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”?

Write an inequality for this sentence the quotient of a number and -5 increased by 4 is at most 8