The Edison Electric Institute has published figures on the number of kilowatt hours used annually by various home appliances. It is claimed that a vacuum cleaner uses an average of 46 kilowatt hours per year. If a random sample of 13 homes included in a planned study indicates that vacuum cleaners use an average of 47 kilowatt hours per year with a standard deviation of 12.9 kilowatt hours, does this suggest at the 0.05 level of significance that vacuum cleaners use, on average, greater than 46 kilowatt hours annually? Assume the population of kilowatt hours to be normal. a. Solve using actual z or t value (whichever is applicable) b. Solve using p-value

Currently patrons at the library speak at an average of 60 decibels. Will this average decline after the installation of a new computer plug in station? After the plug in station was built, the librarian randomly recorded 61 people speaking at the library. Their average decibel level was 57.2 and their standard deviation was 7. What can be concluded at the the a = 0.10 level of significance?

The breaking strengths of cables produced by a certain manufacturer have historically had a mean of 1775 pounds and a standard deviation of 60 pounds. The company believes that, due to an improvement in the manufacturing process, the mean breaking strength, μ, of the cables is now greater than 1775 pounds. To see if this is the case, 90 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1788 pounds. Can we support, at the 0.05level of significance, the claim that the population mean breaking strength of the newly-manufactured cables is greater than 1775 pounds? Assume that the population standard deviation has not changed. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below.  a. State the null hypothesis H0 and the alternative hyposthesis H1. b. Find the value of the test statistic. c. Find the p-value. d. Can we…

Auditors must make judgments about various aspects of an audit on the basis of their own direct experience, indirect experience, or a combination of the two. In a study, auditors were asked to make judgments about the frequency of errors to be found in an audit. The judgments by the auditors were then compared to the actual results. Suppose the following data were obtained from a similar study; lower scores indicate better judgments. Direct Indirect Combination 17.0 16.6 25.2 18.5 22.2 24.0 15.8 20.5 21.5 18.2 18.3 26.8 20.2 24.2 27.5 16.0 19.8 25.8 13.3 21.2 24.2 Use a = 0.05 to test to see whether the basis for the judgment affects the guality of the judgment. State the null and alternative hypotheses. O Ho: Not all the population means are equal. O Ho: HD # Hi * Hc Hi HD = HI= HC O Ho: HD = H1 = Hc O Ho: At least two of the population means are equal. H.: At least two of the population means are different. On = = On :°H O H: Not all the population means are equal. Find the value of…

Assume that human body temperatures are normally distributed with a mean of 98.23°F and standard deviation of .64°F. The hospital uses 100.6°F as the lowest temperature considered to be a fever. What percentage of normal and healthy person's would be considered to have a fever? Does this percentage suggest that a cut off of 100.6°F is appropriate? Physicians want to select a minimum temperature for requiring further medical test. What should the temperature be if we want only 5% of healthy people to exceed it?

The breaking strengths of cables produced by a certain manufacturer have historically had a mean of 1800 pounds and a standard deviation of 90 pounds. The company believes that, due to an improvement in the manufacturing process, the mean breaking strength, μ, of the cables is now greater than 1800 pounds. To see if this is the case, 100 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1818 pounds. Can we support, at the 0.05 level of significance, the claim that the population mean breaking strength of the newly- manufactured cables is greater than 1800 pounds? Assume that the population standard deviation has not changed. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H₁. H :O 1 (b) Determine the…

A non-symmetric dataset has a mean of 200 and a standard deviation of 15.  Find an upper bound for the proportion of data points that are either greater than 230 or less than 170.

The average register transaction at a local coffee house is 6.17 with a standard deviation of 3.25.  If transactions are normally distributed, what percentage are 10.00 or more?