The distance x, in feet, between successive cars on a certain stretch of highway has the following probability density function, where k=1/a and a is the average distance, in feet, between successive cars over some period of time. f(x)=ke−kx, for 0≤x<∞ A transportation planner determines that the average distance between cars on a certain highway is 140 ft. What is the probability that the distance between two successive cars, chosen at random, is 30 ft or less?

step-by-step explanation:

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true