Answer:

And using the cumulative distribution function we got:

The probability that preparation is within 2 minutes of the mean time is 0.134
Step-by-step explanation:
For this case we define the following random variable X= (minutes) for a lab assistant to prepare the equipment for a certain experiment , and the distribution for X is given by:

The cumulative distribution function is given by:

The expected value is given by:

And we want to find the following probability:

And we can find this probability on this way:

And using the cumulative distribution function we got:

The probability that preparation is within 2 minutes of the mean time is 0.134
Set
f
(
x
)
=
0
f(x)=0.
If the polynomial function is not given in factored form:
Factor out any common monomial factors.
Factor any factorable binomials or trinomials.
Set each factor equal to zero and solve to find the
x
x- intercepts.
Answer:
0.253, hope this helps
Step-by-step explanation: