7.A random sample of 49 observations is drawn from a population
with a normal distribution. If the sample mean is 265 and the
sample standard deviation is 57, find the 95% confidence interval
for the population mean.
8. A random sample of 49 observations is drawn from a population
with a normal distribution with a standard deviation of 57. If the
sample mean is 265, find the 95% confidence interval for the
population mean. Compare this confidence interval with the...
(a) Generate n=10 random sample from a population with
normal(40,1) distribution.
(b) For data in part (a) find a 95% confidence interval for mu
(the mean of the population). Can I claim that the mean is 41? If
your answer is "yes" to this question, which one is the mean? 40 or
41?
(c) For data in part (a) find a 99% confidence interval for
sigma (the standard deviation of the population).
Question #3. A random sample of n = 9 is selected from a normal
distribution with μ = 80 and σ=12. What is the probability that the
sample mean will be between 75 and 86? Report to the
thousandths
Question #4. A random sample of n= 4 is obtained from a normal
distribution μ= 30,σ= 8. What is the probability the sample mean
will be smaller than M = 22? Report to the thousandths
Question #5. A random sample of...
The sample variance of a random sample of 50 observations from
a normal population was found to be s2 = 80. Can we
infer at the 1% significance level (i.e., a = .01) that the
population variance is less than 100 (i.e., x < 100) ?
Repeat part a changing the sample size to 100
What is the affect of increasing the sample size?
A sample of n = 36 observations is drawn from a normal
population, with = 500 and = 42. Find P(500
< X̅ < 510).
a.
0.0764
b.
0.8756
c.
0.9236
d.
0.7556
e.
0.4236
A sample of 1600 observations from a normal distribution has
sample mean 50 and sample standard deviation 10.
a. What is the point estimate for the population mean of X?
b. Write a 95% confidence interval for the population mean of X
(Use the t table to obtain the critical value and round to two
decimal places). ( , )
c. Write a 99% confidence interval for the population mean of X
(Use the t table to obtain the critical...
A random sample of 64 observations is to be been drawn from a
distribution with mean
15 and standard deviation 10. Find the probability that the sample
mean, x̅ , will differ
from μ by no more than 2 units in either direction. Interpret your
results.
A simple random sample of 70 items from a population with
σ, = 7 resulted in a sample mean of 33.
If required, round your answers to two decimal places.
a. Provide a 90% confidence interval for the
population mean.
to
b. Provide a 95% confidence interval for the
population mean.
to
c. Provide a 99% confidence interval for the
population mean.
to
A simple random sample of 60 items from a population with σ = 7
resulted in a sample mean of 38.
If required, round your answers to two decimal places.
a. Provide a 90% confidence interval for the
population mean.
_____ to _____
b. Provide a 95% confidence interval for the
population mean.
_____ to _____
c. Provide a 99% confidence interval for the
population mean.
_____ to _____
A simple random sample of 90 items from a population with σ = 7
resulted in a sample mean of 33. If required, round your answers to
two decimal places.
a. Provide a 90% confidence interval for the population mean.
to
b. Provide a 95% confidence interval for the population mean.
to
c. Provide a 99% confidence interval for the population
mean.