What is the length of segment ab?

1. 10.5
2. 4
3. 10
4. 6

Solve this and show you’re work step by step ! -5 3/4+3h< 9 1/4 -

Can someone me out here and the tell me the greatest common factor

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”?