The weekly incomes of trainees at a local company are normally distributed with a mean of $1,100 and a standard deviation of $250. if a trainee is selected at random, what is the probability that he or she earns less than $1,000 a week?
select one:
a. 0.8141
b. 0.1859
c. 0.6554
d. 0.3446

d. 0.3446

Step-by-step explanation:

We need to calculate the z-score for the given weekly income.

We calculate the z-score of $1000 using the formula

From the question, the standard deviation is dollars.

The average weekly income is dollars.

Let us substitute these values into the formula to obtain:

We now read from the standard normal distribution table the area that corresponds to a z-score of -0.4.

From the standard normal distribution table, .

We round to 4 decimal places to obtain: .

Therefore the probability that a trainee earns less than $1,000 a week is .

The correct choice is D.

this is answer of 144 cubic meters