After measuring the duration of many telephone calls, the telephone company found their data was well-approximated by the density function p(x) = 0.2e−0.2x, where x is the duration of a call, in minutes.
(a) What percentage of calls last between 4 and 5 minutes? (Round your answer to the nearest tenth.)
(b) What percentage of calls last 4 minutes or less?
(c) What percentage of calls last 4 minutes or more?
(d) Express the cumulative distribution function in the form shown below.

P(x) = A(x),x

Question

After measuring the duration of many telephone calls, the telephone company found their data was well-approximated by the density function p(x) = 0.2e−0.2x, where x is the duration of a call, in minutes.
 (a) What percentage of calls last between 4 and 5 minutes? (Round your answer to the nearest tenth.)
(b) What percentage of calls last 4 minutes or less?
(c) What percentage of calls last 4 minutes or more? 
(d) Express the cumulative distribution function in the form shown below. 

P(x) = A(x),x < 0
          B(x),0 ≤ x
What is A(x) and B(x)

Woa! i dont even know where to begin. A

anonymous · Answer

i know p(f)=1 but in this case would it equal 100 percent?

unklerhaukus · Answer

$$P(a≤x≤b)=\int\limits_a^b p(x)\text dx$$