Answer:
2.25
Step-by-step explanation:
The total frequency is:
20 + 12 + 6 + 2 = 40
Calculate the probability of each score:
P(X=3) = 20/40 = 0.50
P(X=2) = 12/40 = 0.30
P(X=1) = 6/40 = 0.15
P(X=0) = 2/40 = 0.05
So the expected value is:
E = (3)(0.50) + (2)(0.30) + (1)(0.15) + (0)(0.05)
E = 2.25
3 x 8 = 24
24 + 9 = 33
"the number" = 8
The answer to the question is d
24 makes the equation true
7 = 2n - 2
n= a number so twice a number is 2n and 7 is 2 less than twice this number.
