Answer:
8989
Step-by-step explanation:
Answer:
Margin of error of 0.0485 hours.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.96.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
In this question:

The margin of error is of:



Margin of error of 0.0485 hours.
Answer:
1,778
Step-by-step explanation:
Let C and S represent the cost and salvage value of Truck B, respectively. Let X represent the number of miles per year that answers the question.
Truck A's cost for 10 years is ...
A = C+600 +(0.06)(2.25)(10X) -(S+200)
Truck B's cost for 10 years is ...
B = C +(0.07)(2.25)(10X) -S
We want to find X such that Truck A's cost is lower, so ...
C -S +1.35X +400 < C -S +1.575X
400 < 0.225X
1777 7/9 < X
1778 miles driven per year (or more) makes Truck A a better option.