The average amount that a college student spends on a textbook is $205. What is the probability that a students spends between $10 and $310

Complete question :

The average amount that a college student spends on a textbook is $205 with a

standard deviation of $35. What is the probability that a student spends:

A. between $10 and $310?

0.999

Step-by-step explanation:

Mean, m = 205 ; Standard deviation, s = 35

Z = (x - m) / s

x = 310

Z = (310 - 205) / 35 = 3

P(z < 3) = 0.99865

x = 10

Z = (10 - 205) / 35 = - 5.57

P(Z < - 5.5)

P(z < 3) - P(z < - 5.5)

0.99865 - 0

= 0.999