a. What percent of people earn less than $40000?
Solution: Let S be the random variable of a salary of employee (in $), S ~ N(50000,20000). Then the random
variable X =−50000
20000
~N(0,1).
( < 40000) = ( <
40000 − 50000
20000 ) = ( < −0.5) = (−0.5) = 0.3085375.
Here Φ(x) denotes the cumulative distribution function of a standard normal distribution.
Answer: 31%.
b. What percent of people earn between $45000 and $65000?
Solution:
(45000 < < 65000) = (
45000 − 50000
20000 < <
65000 − 50000
20000 ) = (−0.25 < < 0.75)
= (0.75) − (−0.25) = 0.7733726 − 0.4012937 = 0.3720789.
Answer: 37%.
c. What percent of people earn more than $70000?
Solution:
( > 70000) = ( >
70000 − 50000
20000 ) = ( > 1) = 0.8413447.
Answer: 84%.
Answer:
1000
Step-by-step explanation:
the math
Answer:
Yes. Have the same distribution.
Step-by-step explanation:
Given that X is a random day of the week, coded so that Monday is 1, Tuesday is 2, etc. (so X takes values 1, 2,..., 7, with equal probabilities).
Y is the next day after X
So Y can be written as X+1
But since highest value is 7, we can write
Y = X+1 mod 7
i.e. whenever X=7, Y= 8= 1 again.
Thus Y can take values as
Y 1 2 3 4 5 6 7
P(Y) = P(X+1) = 1/7
i.e. Y also has the same distribution as X
Answer: an endless cylinder with radius 4 mm and centerline
Answer:
B. 1 5/6
Step-by-step explanation: