If x, the time (in minutes)to complete an oil change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$30), then the mean of this distribution is __________________.
A)50
B)25
C)10
D)15
E)5

Question

Quizplus · Accepted Answer

The mean of a uniform distribution is calculated as (a + b) / 2, where a and b are the minimum and maximum values of the distribution, respectively. Here, a = 20 and b = 30, so the mean is (20 + 30) / 2 = 25.

If X, the Time (In Minutes)to Complete an Oil Change ≤\le≤

If X, the Time (In Minutes)to Complete an Oil Change $\le$