Let X be the commuting time for the student. We know that $X\sim N(30, (5)^2)$ . Then, the normal probability density function for the random variable X is given by

$f(x) = \frac{1}{\sqrt{2\pi(5)^{2}}}\exp[-\frac{(x-\mu)^{2}}{2(5)^{2}}]$ . We are seeking the probability P(X>35) because the student leaves home at 8:25 A.M., we want to know the probability that the student will arrive at the college campus later than 9 A.M. and between 8:25 A.M. and 9 A.M. there are 35 minutes of difference. So,

$P(X>35) = \int\limits_{35}^{\infty}f(x)dx$ = 0.1587

To find this probability you can use either a table from a book or a programming language. We have used the R statistical programming language an the instruction pnorm(35, mean = 30, sd = 5, lower.tail = F)

6 0

4 years ago

Roman has 2 red pencils in his backpack if this is 25% of the total number of pencils how many pencils are in his backpack. you

lys-0071 [83]

8 because 25% is 1/4 of how much he has so just multiply 2 by 4

3 0

3 years ago