Answer to Question #58062 in Statistics and Probability for Christbeauty

Question

The mean and range of the set of numbers 1.20, 1.00, 0.90, 1.40, 0.80, 0.80, 1.20 & 1.10 are m and r respectively. find m+r
1.69
1.68
1.67
1.66

The score of 5 students in an examination are 6, 5, 8, 7 & 4 find the variance
3
2
2.5
4.5

The mean of four number is 5 and the mean deviation is 3. find the fourth number if the mean deviation of the first three number is 2
12
20
11
15