Construct a 99% confidence interval on the population variance
and the population standard deviation for the data listed
below:
91.8, 112.1, 138.3, 90.6, 136.6, 113.6, 101.5, 123.6, 81.4,
119.2, 111.4, 89.4, 110.5, 80.5, 94.8, 117.0, 105.7, 146.6, 138.6,
99.9, 106.6
Find the 90% confidence interval for the standard deviation of
the lengths of pipes if a sample of 22 pipes has a standard
deviation of 10.6 inches.
a. (8.3, 13.8)
b. (8.5, 13.3)
c. (8.5, 14.3 )
d. (8.1, 15.3)
The width of a confidence interval will be:
A) Wider when the sample standard deviation is small than when s
is large
B) Narrower for 95% confidence than 99% confidence
C) Narrower for 95% confidence than 90% confidence
C) Wider for a sample size of 100 for a sample size of 50
Find the 99% condence interval for the standard deviation of the
weights of 25
gallon containers of motor oil if a sample of 15 containers has a
variance of 3.2.
The weights are given in ounces. Assume the variable is normally
distributed.
the standard deviation of the diameter of 28 oranges was 0.34
inch. find the 99% confidence interval of the true standard
deviation of the diameter of the orages.
Find the 80% confidence interval for the standard deviation of
the ages of seniors at Oak Park College if a random sample of 21
students has a standard deviation of 2.3 years. Assume the variable
is normally distributed.
a.) (1.9,2.9)
b.) (2.6, 3.3)
c.) (3.7,8.5)
d.) (2.6, 7.0)
Find the 80% confidence interval for the standard deviation of
the ages of seniors at Oak Park College if a random sample of 21
students has a standard deviation of 2.3 years. Assume the variable
is normally distributed.
The 99% confidence interval for a population proportion is
[0.645, 0.737]. Find the standard error involved in this confidence
interval. (Z_{a/2}Za/2 = 2.58). Please show how you
arrive at your answer so I can understand how to calculate this. If
you know the excel commands, that would be helpful as well.
A. How many samples do you need to create a 99% confidence
interval for u with a margin of error fo 10 and standard deviation
of 28?
B. Five a 95% percent confidence interval for the true mean if
the sample mean is 86.5, the sample size is 70, and the standard
deviation is 12.2.
A. How many samples do you need to create a 99% confidence
interval for u with a margin of error fo 10 and standard deviation
of 28?
B. Five a 95% percent confidence interval for the true mean if
the sample mean is 86.5, the sample size is 70, and the standard
deviation is 12.2.