What is the mean absolute deviation of the data set below
20,30,20,60​

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

Having a hard time understanding this question (see attachment).