Looking for an answer or equation for this: n=-3 r=64 w=5

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”?

Ntriangle abc, m∠a = 35° and m∠b = 40°, and a=9. which equation should you solve to find b?

What is the domain of the of the exponential function shown below?