A)
You intend to estimate a population mean \(\mu\) with the following sample.
78.6
93.4
70.5
82.9
66.9
102.8
You believe the population is normally distributed. Find the 99% confidence interval.
Enter your answer as an open-interval (i.e., parentheses) accurate to two decimal
places (because the sample data are reported accurate to one decimal place).
99% C.I=
Answer should be obtained without any preliminary rounding. However, the critical
value may be rounded to 3 decimal places.
B)
You measure 32 dogs' weights, and find they have a mean weight of 77 ounces.
Assume the population standard deviation is 13.6 ounces. Based on this, what is the
maximal margin of error associated with a 90% confidence interval for the true
population mean dog weight.
Give your answer as a decimal, to two places
\(\pm\) ______ ounces
C)
In a survey, 17 people were asked how much they spent on their child's last birthday
gift. The results were roughly bell-shaped with a mean of $34 and standard deviation of
$4. Find the margin of error at a 98% confidence level.
Give your answer to two decimal places.
D)
You want to obtain a sample to estimate a population proportion. At this point in time,
you have no reasonable estimate for the population proportion. You would like to be
99% confident that you estimate is within 2% of the true population proportion. How
large of a sample size is required?
n=
Do not round mid-calculation. However, use a critical value accurate to three decimal
places.
E
A political candidate has asked you to conduct a poll to determine what percentage of
people support her.
If the candidate only wants a 5% margin of error at a 99% confidence level, what size of
sample is needed?
Give your answer in whole people.
F)
If n=480 and \(\hat{p}\) (p-hat) =0.12, find the margin of error at a 90% confidence level
Give your answer to three decimals
