Answer: 25/36
Step-by-step explanation:
Multiply:
2/3 * 10/24 = 20/72 = 5/18
-3 1/8 * -4/5 = 5/2
5/18 * 5/2 = 25/36
Answer:
Mean = 1.57
Variance=0.31
Step-by-step explanation:
To calculate the mean and the variance of the number of successful surgeries (X), we first have to enumerate the possible outcomes:
1) Both surgeries are successful (X=2).

2) Left knee unsuccessful and right knee successful (X=1).

3) Right knee unsuccessful and left knee successful (X=1).

4) Both surgeries are unsuccessful (X=0).

Then, the mean can be calculated as the expected value:

The variance can be calculated as:

B.120 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
B:S = 4x:3x
4x - 3x = 3
x = 3
They were 12 & 9.
Add 5 to that.
So he’s now 17 and she’s 14