A coin-operated drink machine was designed to discharge a mean of 9 ounces of coffee per cup. In a test of the machine, the discharge amounts in 20 randomly chosen cups of coffee from the machine were recorded. The sample mean and sample standard deviation were 8.95 ounces and 0.13 ounces, respectively. If we assume that the discharge amounts are normally distributed, is there enough evidence, at the 0.05 level of significance, to conclude that the true mean discharge, u, differs from 9 ounces? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H, :0 H :0 (b) Determine the type of test statistic to use. (Choose one) ▼ O=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) ? (d) Find the p-value. (Round to three or more decimal places.) (e) At the 0.05 level of significance, can we conclude that the true mean discharge differs from 9 ounces? O Yes ONo olo

light examined data on employment and answered questions regarding why workers separate from their employes. According to the article, the standard deviation of the length of time that women with one job are employed during the first 8 years of their career is 92 weeks. Length of time employed during the first 8 years of career is a left skewed variable. For that variable, do the following tasks. A. determine the sampling distribution of the sample mean for simple random samples of 50 women with one job. Explain your reasoning B. Obtain the probability that the sampling error made in estimating the mean length of time employed by all women with one job by that of a random sample of 50 such women will be at most 20 weeks

Suppose that blood chlorine concentration (mmol/L) has a normal distribution with mean=98 and standard deviation=7. For a sample of n=40, what is the corresponding mean and standard deviation of the sampling distribution?

Humerus bones from the same species of animal have approximately the same length-to-width ratios. It is known that Species A has a mean ratio of 5.9. Suppose that 100 fossil humerus bones were unearthed at a site where Species A is known to have flourished. (We assume that all bones are from the same species.) The length-to-width ratios of these bones have a sample mean 5.6 and sample standard deviation 0.25.   Can we conclude that the mean ratio of these bones is significantly smaller than those of Species A? Test with a 0.01 significance level.   What is the standard error?

In 16 women with diabetes, the morning blood sugar mean was 49.4  with a standard deviation of 24.0. In normal healthy women, the mean was 47.0. From the sample information, can we conclude that the blood sugar mean in women with rheumatoid arthritis is greater than that in normal women? Assume a significance level of 0.05.

The means of the number of revolutions per minute of two competing engines are to be compared. Thirty engines are randomly assigned to be tested. Both populations have normal distributions. Table 10.4 shows the result. Do the data indicate that Engine 2 has higher RPM than Engine 1? Test at a 5% level of significance. Engine      Sample Mean Number of RPM         Population Standard Deviation  1                      1,500                                                       50  2                      1,600                                                       60

According to Current Population Reports, the population distribution of number of years of education for self-employed individuals in the United States has a mean of 13.6 and a standard deviation of 3.0.  Find the mean and standard error of the sampling distribution of ȳ for a random sample of  9 residents.

An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 4.3 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 26 engines and the mean pressure was 4.7 pounds/square inch with a standard deviation of 0.8. A level of significance of 0.01 will be used. Assume the population distribution is approximately normal. Find the value of the test statistic. Round your answer to three decimal places.