Question

You have been recording how many miles you get per tank of gas, and you have found a mean of 297 and a standard deviation of 23. Use this information to answer the following question.

What is the probability you will get 300 miles out of a tank of gas?

Answer 1

P(z<Z) table :

x : total miles for the tank of gas

you get 300 miles out of tank of gas : x >= 300 miles

P(x>=300) = 1 - P(x<300)

P(x<300)

z=(x-mean)/SD

for x=300

z=(300-297)/23 = 0.13

P(x<300) = P(z<0.13) = 0.5517 {from table}

P(x>=300) = 1 - P(x<300) = 1 - 0.5517

= 0.4483

therefore the probability you will get 300 miles out of a tank of gas = 0.4483

(please UPVOTE)