In the middle:
x-coordinate= {7-(-1)}/2= 4
y-coordinate= (8-2)/2= 3
So centre is (4,3)
Answer: 3421.19
Step-by-step explanation:
look up cylinder formula and r= radius which is just the diameter cut in half
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:
