What is the positive square root of 0.09?

How to use order of operation in 20 divide by 4 multiply 5 = 1

With alll of except for the 2 that i did already

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”?