Is the data set approximately periodic? If so, what are its period and amplitude? not periodic

periodic with a period of 4 and an amplitude of about 20

periodic with a period of 4 and an amplitude of about 30

periodic with a period of 5 and an amplitude of about 25

What is the perimeter of trapezoid jklm? + units 2 + + units 9 + units 9 + + units

Find the multiplicative inverse of 8-12i

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. without looking in the hat, dan takes out a marble at random. he replaces the marble and then takes out another marble from the hat. what is the probability that dan takes out a blue marble in both draws?