In a group of 21 students, 8 students take art courses, 7 students take music courses. two students take both courses. a student is chosen randomly from this group. what is the probability that the student takes either art or music courses?

5/7

8/21

13/21

2/7

The table shows population statistics for the ages of best actor and best supporting actor winners at an awards ceremony. the distributions of the ages are approximately bell-shaped. compare the z-scores for the actors in the following situation. best actor best supporting actor muequals42.0 muequals49.0 sigmaequals7.3 sigmaequals15 in a particular year, the best actor was 59 years old and the best supporting actor was 45 years old. determine the z-scores for each. best actor: z equals best supporting actor: z equals (round to two decimal places as needed.) interpret the z-scores. the best actor was (more than 2 standard deviations above more than 1 standard deviation above less than 1 standard deviation above less than 2 standard deviations below) the mean, which (is not, is) unusual. the best supporting actor was (less than 1 standard deviation below more than 1 standard deviation above more than 2 standard deviations below more than 1 standard deviation below) the mean, which (is is not) unusual.

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.