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
Answer:
Step-by-step explanation:
<u>Sum of n terms formula:</u>
<u>Solving for n</u>
- 3480 = 1/2n(9 + 165)
- 3480 = 87n
- n = 3480/87
- n = 40
Answer:
I cannot see the question clearly. But I know how to do .
Answer:
0.0021
Step-by-step explanation:
move decimal three to the left
2x = 48, 3x = 72, 4x = 96, 6x = 144
2x + 3x + 4x + 6x = 360
15x = 360
x = 24
2x = 2(24) = 48
3x = 3(24) = 72
4x = 4(24) = 96
6x = 6(24) = 144
