Find the standard deviation of the ages of soprano singers to the nearest tenth. the ages of soprano singers in a town choir are 63, 42 ,28,45,36,48,32,40,57 & 49

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m

The box plots show the average speeds, in miles per hour, for the race cars in two different races. which correctly describes the consistency of the speeds of the cars in the two races?

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”?