Answer:

Step-by-step explanation:
The general formula for the twelfth term of a geometric sequence is:

Where
is the first term and r is the common ratio
In this case we know that:

The equation is:

So for
we look for 



Answer:
P(X<118.81)=0.0803
Step-by-step explanation:
Assuming the distribution for the mean life is approximately normal, with mean 120 months and variance 64 months^2, we can calculate the parameters for a sampling distribution with sample size = 89 computers.
The sampling distribution mean will be equal to the mean for a single computer:

The standard deviation will be adjusted by the sample size as:

With these parameters, we can calculate the z-score for X=118.81.

Then, the probability that the mean of a sample of 89 computers is less than 118.81 months is:

Answer:
44.9%
Step-by-step explanation:
you can find the probability by dividing the total number of people by the number of people who have run a red light:
385/857
simplify into a decimal:
0.449
convert into a percent to get your answer:
44.9%