Answer:
Option B is the correct choice.
Step-by-step explanation:
The graph is attached below.
We have to find the
intercept meaning the value of the point on
when 
So we will put the value of zero
instead of
in our given equation.
So here we have solved it algebraically.

Putting 


Multiplying
both sides.

Adding
both sides.

Dividing with
both sides.

So the x-intercept of the given equation is
which can be written as
in terms of coordinates.
Option B
is the correct choice.
Answer:

Step-by-step explanation:
we are given a exponential equation

we want to figure out x
remember that,

thus
take
both sides:

use the formula:

by using calculator

Answer:
0.3108 is the probability that the sample mean is between 7.8 and 8.2 minutes.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 8 minutes
Standard Deviation, σ = 2.5 minutes
Sample size, n = 25
We are given that the distribution of time spent is a bell shaped distribution that is a normal distribution.
Formula:

Standard error due to sampling =

P(sample mean is between 7.8 and 8.2 minutes)

0.3108 is the probability that the sample mean is between 7.8 and 8.2 minutes.