The average life for a particular brand of car battery is given by the following probability density function where t is in years. Find the probability that a battery chosen at random lasts between 2 and 7 years. Round your answer to two decimal places.
A)1.72
B)0.43
C)0.54
D)0.34
E)0.65

Question

The average life for a particular brand of car battery is given by the following probability density function where t is in years.  ​Find the probability that a battery chosen at random lasts between 2 and 7 years. Round your answer to two decimal places. ​
A)1.72 
B)0.43 
C)0.54 
D)0.34 
E)0.65

Quizplus · Accepted Answer

We need to calculate the integral of the probability density function over the interval (2,7).

∫ from 2 to 7 (1/25)(t-2)(5-t) dt

= 0.43 (rounded to two decimal places)

Therefore, the answer is B.

The Average Life for a Particular Brand of Car Battery