In a recent study of animal sleep times at the zoo, the mean amount of sleep per night is 6.3 hours with a standard deviation of 2.1. If 23 animals are selected, find the probability that the mean sleep time per night is greater than 8 hours.

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

When you are making a circle graph by hand, how do you convert a number for a part into its corresponding angle measure in the circle graph? when you are making a circle graph by hand, what should you do if one of your angle measures is greater than 180°?

Just tell me how to set up the equation.