answer the questions fully

1. Andy has grades of 84, 95, and 86 on three math tests. What grade must he obtain on the next test to have an average of exactly 90 for the four tests?

2. The probability that you will win a certain game is 0.8. If you play the game 12 times, what is the probability that you will win at least 7 times?

3. The weekly salaries of six employees at McDonalds are $240, $240, $290, $180, $240, $200. For these six salaries, find: (a) the mean (b) the median (c) the mode.

4. The scores on a mathematics test were 70, 55, 61, 80, 85, 72, 65, 40, 74, 68, 61, 67, 81, 83, 87, 88, 89, 90, 98, and 100. Construct a frequency table using a binwidth of 10.

5. Calculate the sample mean, sample variance, and sample standard deviation for the following data set: 2, 2, 0, 5, 1, 4, 1, 3, 0, 0, 1, 4, 4, 0, 2, 0, 5, 1, 4, 2, 0, 5, 1, 4, 2, 1, 0.