68. Traveling to work How long do people travel each day to get to work ? The following table gives the average travel times to
work (in minutes ) for workers in each state and the District of Columbia who are at least 16 years old and don't work at home .
a) Make a histogram to display the time travel time data using intervals of within 2 minutes, starting at 14 minutes.
b) Describe the shape of the distribution. What is the most common interval of travel times?
a) Make a histogram to display the time travel time data using intervals of within 2 minutes, starting at 14 minutes.
b) Describe the shape of the distribution. What is the most common interval of travel times?
1 answer:
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Answer:
Step-by-step explanation:
We can directly substitute y of the first equation to the second equation.
-2x - 1 = 3x - 16
5x = 15
x = 3
Substituting back to any of the two equations, we get y = -2(3)-1 = -7. If you check with the second equation, y = 3(3)-16 = -7 as well.
Therefore .
Answer:
a) A sample size of 5615 is needed.
b) 0.012
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error is:
99.5% confidence level
So , z is the value of Z that has a pvalue of
, so
.
(a) Past studies suggest that this proportion will be about 0.2. Find the sample size needed if the margin of the error of the confidence interval is to be about 0.015.
This is n for which M = 0.015.
We have that
A sample size of 5615 is needed.
(b) Using the sample size above, when the sample is actually contacted, 12% of the sample say they are not satisfied. What is the margin of the error of the confidence interval?
Now .
We have to find M.