If the population standard deviation, sigma, is known, then the population mean has a normal distribution, and you will be using the z-score formula for sample ...

Solution Summary

This solution compares test claims about a population mean when the population standard deviation is known versus unknown.

A sample mean, sample size, and population standard deviation are given. Use the P-value approach to perform a one-mean z-test about the mean of the population from which the sample was drawn.
x bar= 78, n = 28, sigma = 11, Hnought: mu=72, Hone: mu>72 , alpha = 0.01
First find the proper z value then use this to find the

Consider the following hypothesis test:
H0: u>= 1.25
Ha: u< 1.25
A sample of 49 provides a sample mean of 1.19 and a previous populationstandarddeviation of 0.14. Answer the following questions:
a. At a=0.01, what is the critical value?
b. Compute the value of the test statistic t.
c. What is the p-value?
d.

Why is it important to know the standarddeviation for a given sample? What do researchers learn about a normal distribution from knowledge of the standarddeviation? A sample of n=20 has a mean of M = 40. If the standarddeviation is s=5, would a score of X= 55 be considered an extreme value? Why or why not?
Can you please d

Kannon Camera has developed a new camera that it claims can take an average of more than 10 photographs per second. You decide to evaluate the company's claim. A sample of 16 cameras was used; they were tested and found to have a mean number of photographs per second of 10.50. Previous tests of cameras of this type revealed that

Please see the attachment for proper formatting and symbols.
7.45 #5. Find a value, X0, such that µ = 160 and o2 = 256
a)P(X < X0) = 0.16
b) P(X-< X0) = 0.75
7.64 #16. A sample of size n = 20 is randomly selected from a normal population with mean µ = 90 and standard deviation = 5. Find the following:-
a. P (x > 95) t

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A group of young businesswomen wish to open a high fashion boutique in a vacant store, but only if the average income of households in the area is at least $25,000. A random sample of 9 households showed the following results:
$28,000 $23,000 $24,000 $24,000 $27,000 $26,000 $26,000 $25,000 $22

The average length of time for students to register for classes at a certain college has been 50 minutes. A new registration procedure is being tried. A random sample of 12 students resulted in an average registration time of 42 minutes with a standarddeviation of 11.9. Assume the distribution of registration times are norma

There is uneasiness that the users of paper coupons are different from the users of e-coupons (coupons disseminated by means of the Internet). One survey recorded the age of each person who redeemed a coupon along with the type (either electronic or paper). The sample of 35 e-coupon users had a mean age of 33.6 years with a stan

A sample of 40 observations is selected from one somewhat normal population. The sample mean is 102 and the sample standarddeviation is 5. A sample of 50 observations is selected from a second source. The sample mean was 99 and the standarddeviation was 6. Conduct a test of the hypothesis using the .04 level of significance.