What is the mean absolute deviation of the data set? {12, 10, 10, 8, 6, 7, 7, 12}
A 1
B 2
C 6
D 9

B. 2

To find MAD, find the mean of the set, then find how far each number is from the mean. Next, find the mean of THAT set of numbers. Yea, I know it's a bit confusing... don't worry!

Find the mean of the set:

12 + 10 + 10 + 8 + 6 + 7 + 7 + 12

72

72 / 8

9

Find how far each number is from 9:

12 - 9 = 3

10 - 9 = 1

10 - 9 = 1

9 - 8 = 1

9 - 6 = 3

9 - 7 = 2

9 - 7 = 2

12 - 9 = 3

Find the mean of that number set:

{3, 1, 1, 1, 3, 2, 2, 3}

3 + 1 + 1 + 1 + 3 + 2 + 2 + 3

16

16 / 8

2

So the answer is 2!

Not so hard after all   :D

blue marble is 15 times out of 50 = 15/50 reduces to 3/10

landing on tails is 24 out of 50 = 24/50 reduces to 12/25

to find the probability of both multiply together:

3/10 x 12/25 = 3 x 12 / 10 x 25 = 36/250

if you multiplied the numerator and denominator by 10 you get 360/2500.

the answer is 360/2500