Answer:
a. mean = 1000
standard deviation = 4358.9
b. expected value of average damage bar Y = 1000
probability bar y exceeds 2000 = 0.011
Step-by-step explanation:
we have p1 = 95%, y1 = 0, p2 = 5%, y2 = 20000
Mean = (0.95 * 0) + (0.05 * 20000)
= 1000
var(y) = E(y²) - E(Y)²
= we solve for E(y)²
= 0²*0.95 + 20000²*0.05
= 0 + 20000000
then the variance of y = 20000000 - 1000²
=20000000-1000000
= $19000000
standard deviation is the square root of variance
= √19000000
= 4358.9
2.
a. Expected value of average is also the mean = 1000
b. we are to find probability that barY exceeds 2000

= 1000/435.889
= 2.29
1-p(z≤2.29)
= 1 - 0.989
= 0.011
so the probability that barY exceeds 2000 is 0.011
The answer to that is - 10
It is said that 85% of the students liked reading mystery stories. This means the remaining 15% don't like to read these stories. If there are 30 students belonging to the second category, then the number of students who liked reading mystery stories is (30/0.15)*0.85 equal to 170 students out of 200 students.
the answer should be A because the sea level has rised
Answer:
325 km
Step-by-step explanation:
Given the scale :
1 : 4 ,000, 000
1cm measure in map = 4000000 on the ground
From the map :
Distance between Leeds and London = 8.125 cm
The actual distance on ground can be calculated thus :
1cm = 4,000,000
8.125cm = x
Cross multiply
x = 32500000 cm
Converting to kilometers :
1 km = 100,000 cm
x = 32500000
Cross multiply
100,000x = 32500000
x = 32500000 / 100000
x = 325
Hence, actual distance between Leeds and London is 325 km