You need to find circumference, so you would multiply the diameter by pi. So your answer is 212pi feet or 666.02 feet
Answer:

And we have a sample size of n =81. We want to estimate the standard error of the sampling distribution
and for this case we know that the distribution is given by:

And the standard error would be:

And replacing we got:

Step-by-step explanation:
For this case we know the population deviation given by:

And we have a sample size of n =81. We want to estimate the standard error of the sampling distribution
and for this case we know that the distribution is given by:

And the standard error would be:

And replacing we got:

Answer:
dist = 60 mph * (3.5 hrs) = 210 miles
The answer is 210 Miles
(-7)*(2/5 + (-3/7))
= -14/5 + 3
=1/5