Applied Statistics and Probability for Engineers 6th Edition solutions

Applied Statistics and Probability for Engineers 6
Consider the following computer output. Two-Sample T-Test and Cl Sample N Mean StDev SE Mean 1 20 11.87 2.23 ? 2 20 12.73 3.19 0.71 Difference \(=\mathrm {mu}\ (1)-\mathrm {mu}\ (2)\) Estimate for difference: -0.860 95% CI for difference: (?, ?) T-Test of difference \(= 0\ (\math

Applied Statistics and Probability for Engineers 6
Consider the following computer output. Two-Sample T-Test CI Sample N Mean StDev SE Mean 1 16 22.45 2.98 0.75 2 25 24.61 5.36 1.1 Difference \(=\mathrm {mu}\ (1)-\mathrm {mu}\ (2)\) Estimate for difference: 2.16 T-Test of difference \(= 0\ (\mathrm{vs} <)\): T-Value \(=-1.65\ \mathrm

Applied Statistics and Probability for Engineers 6
An article in the Journal of Materials Engineering [1989, Vol. 11(4), pp. 275282] reported the results of an experiment to determine failure mechanisms for plasma-sprayed thermal barrier coatings. The failure stress for one particular coating (NiCrAlZr) under two different test conditions is as follo

Applied Statistics and Probability for Engineers 6
A procurement specialist has purchased 25 resistors from vendor 1 and 35 resistors from vendor 2 . Fach resistor's resistance is measured with the following results (ohm): Vendor Vendor 2

Applied Statistics and Probability for Engineers 6
A liquid dietary product implies in its advertising that using the product for one month results in an average weight loss of at least 3 pounds. Eight subjects use the product for one month, and the resulting weight loss data follow. Use hypothesis-testing procedures to answer the following questions

Applied Statistics and Probability for Engineers 6
The breaking strength of yarn supplied by two manufacturers is being investigated. You know from experience with the manufacturers' processes that \(\sigma_{1}=5\) psi and \(\sigma_{2}=4\) psi. A random sample of 20 test specimens from each manufacturer results in \(\overline{x_{1}}=88\) psi and \(\o

Applied Statistics and Probability for Engineers 6
The Salk polio vaccine experiment in 1954 focused on the effectiveness of the vaccine in combating paralytic polio. Because it was believed that without a control group of children, there would be no sound basis for evaluating the efficacy of the Salk vaccine, the vaccine was administered to one grou

Applied Statistics and Probability for Engineers 6
Consider Supplemental Exercise 10-98. Suppose that prior to collecting the data, you decide that you want the error in estimating \(\mu_{1}-\mu_{2}\) by \(\bar{x}_{1}-\bar{x}_{2}\) to be less than 1.5 psi. Specify the sample size for the following percentage confidence: (a) 90% (b) 98% (c) Commen

Applied Statistics and Probability for Engineers 6
Problem 101SE A random sample of 1500 residential telephones in Phoenix in 1990 indicated that 387 of the numbers were unlisted. A random sample of 1200 telephones in the same year in Scottsdale indicated that 310 were unlisted. (a) Find a 95% confidence interval on the difference in the two propor

Applied Statistics and Probability for Engineers 6
Problem 102SE In a random sample of 200 Phoenix residents who drive a domestic car, 165 reported wearing their seat belt regularly, and another sample of 250 Phoenix residents who drive a foreign car revealed 198 who regularly wore their seat belt. (a) Perform a hypothesis-testing procedure to dete

Applied Statistics and Probability for Engineers 6
Problem 103SE Consider the previous exercise, which summarized data collected from drivers about their seat belt usage. (a) Do you think there is a reason not to believe these data? Explain your answer. (b) Is it reasonable to use the hypothesis-testing results from the previous problem to draw an

Applied Statistics and Probability for Engineers 6
The manufacturer of a new pain relief tablet would like to demonstrate that its product works twice as fast as the competitor's product. Specifically, the manufacturer would like to test \(H_0\ :\ \mu_1=2\mu_2\) \(H_1\

Applied Statistics and Probability for Engineers 6
Go Tutorial Two machines are used to fill plastic bottles with dishwashing detergent. The standard deviations of fill volume arc known to be \(\sigma_{1}=0.10\) fluid ounces and \(\sigma_{2}=0.15\) fluid ounces for the two machines, respectively. Two random samples of \(n_{1}=1\) bottles from machine

Applied Statistics and Probability for Engineers 6
Suppose that you are testing \(H_0\ :\ \mu_1=\mu_2\) versus \(H_1\ :\ \mu_1\ne\mu_2\), and you plan to use equal sample sizes from the two populations. Both populations are assumed to be normal with unknown but equal variances. If you use \(\alpha=0.05\) and if the true mean \(\mu_{1}=\mu_{2}+\sigma\

Applied Statistics and Probability for Engineers 6
Consider the situation described in Exercise 10-87. (a) Redefine the parameters of interest to be the proportion of lenses that are unsatisfactory following tumble polishing with polishing l uids 1 or 2. Test the hypothesis that the two polishing solutions give different results using \(\alpha =

Applied Statistics and Probability for Engineers 6
Consider the fire-fighting foam-expanding agents investigated in Exercise 10-20, in which five observations of each agent were recorded. Suppose that if agent 1 produces a mean expansion that differs from the mean expansion of agent 1 by 1.5, you would like to reject the null hypothesis with probabil

Applied Statistics and Probability for Engineers 6
A fuel-economy study was conducted for two Cerman automobiles, Mercedes and Volkswagen. One vehicle of each brand was selected, and the mileage performance was observed for 10 tanks of fuel in each car. The data are as folLows (in miles per gallon): Mercedes Volkswagen

Applied Statistics and Probability for Engineers 6
An experiment was conducted to compare the filling capability of packaging equipment at two different wineries. Ten bottles of pinot noir from Ridgecrest Vineyards were randomly selected and measured, as were 10 bottles of pinot noir from Valley View Vineyards. The data are as follows (fill volume is

Applied Statistics and Probability for Engineers 6
A Rockwell hardness-testing machine presses a tip into a test coupon and uses the depth of the resulting depression to indicate hardness. Two different tips are being compared to determine whether each provides the same Rockwell C-scale hardness readings. Nine coupons are tested with both tips being

Applied Statistics and Probability for Engineers 6
Two different gauges can be used to measure the depth of bath material in a Hall cell used in smelting aluminum. Each gauge is used once in 15 cells by the same operator. Cell Gauge 1 Gauge 2 Cell Gauge 1 Gauge 2 1 46 in. 47 in. 9 52 in. 51 in. 2 50 53 10 47 45 3 47 45 11 49

Applied Statistics and Probability for Engineers 6
An article in the Journal of the Environmental Engineering Division [Distribution of Toxic Substances in Rivers (1982, Vol. 108, pp. 639 649)] investigated the concentration of several hydrophobic organic substances in the Wolf River in Tennessee. Measurements on hexachlorobenzene (HCB) in nanograms

Applied Statistics and Probability for Engineers 6
Consider the foam thickness data from Exercise 10-39. Is there any indication that the variances of foam thickness are different at the two different levels of temperature?

Applied Statistics and Probability for Engineers 6
Consider the grinding force data in Exercise Is there any indication that the variances of grinding force are different at the two different levels of temperature?

Applied Statistics and Probability for Engineers 6
Consider the seat belt usage data in Exercise 10-102. Find Cls on the difference in the proportions of seat belt usage for drivers of foreign and domestic cars using both procedures described in this chapter. Compare the lengths of these two intervals and comment on any difference you may observe.

Applied Statistics and Probability for Engineers 6
Consider the unlisted telephone number data in Exercise . Find CIs on the difference in the proportions of unlisted telephone numbers for Phoenix and Scottsdale resjdents using both procedures described in this chapter. Compare the lengths of these two intervals and comment on any difference you may

Applied Statistics and Probability for Engineers 6
Three different pesticides can be used to control pest infestation of grapes. It is suspected that pesticide 3 is more effective than the other two. In a particular vineyard, three different plantings of pinot noir grapes are selected for study. The following results on yield are obtained:

Applied Statistics and Probability for Engineers 6
Suppose that you wish to test \(H_0\ :\ \mu_1=\mu_2\) versus \(H_1\ :\ \mu_1\ne\mu_2\), where \(\sigma_{1}^{2}\) and \(\sigma_{2}^{2}\) are known. The total sample size is to be determined, and the allocation of observations to the two populations such that \(n_{1}+n_{1}=N\) is to be made on the bas

Applied Statistics and Probability for Engineers 6
Suppose that you wish to test the hypothesis \(H_0\ :\ \mu_1=\mu_2\) versus \(H_1\ :\ \mu_1\ne\mu_2\), where both variances \(\sigma_{1}^{2}\) and \(\(\sigma_{2}^{2}\)\) are known. A total of \(n_{1}+n_{2}=N\) observations can be taken. How should these observations be allocated to the two population

Applied Statistics and Probability for Engineers 6
Suppose that you wish to test \(H_0: \mu=\mu_0\) versus \(H_1: \mu \neq \mu_0\), where the population is normal with known \(\sigma\). Let \(0<\varepsilon<\alpha\), and define the critical region so that you will reject \(H_0\) if \(z_0>z_{\varepsilon}\) or if \(z_0<-z_{\alpha-\varepsilon}\) where \(

Applied Statistics and Probability for Engineers 6
Problem 122MEE Construct a data set for which the paired t-test statistic is very large, indicating that when this analysis is used, the two population means are different, but t0 for the two-sample t-test is very small so that the incorrect analysis would indicate that there is no significant diff

Applied Statistics and Probability for Engineers 6
In some situations involving proportions, you are interested in the ratio \(\theta=P_{1} / p_{2}\) rather than the difference\( P_{1}-p_{2} \text {. }\). Let \(\widehat{\theta}=\vec{P}_{1} / \overline{P_{2}}\) has an approximate normal distribution with the mean \((n / \theta)\) and variance

Applied Statistics and Probability for Engineers 6
Problem 124MEE Derive an expression for ? for the test of the equality of the variances of two normal distributions. Assume that the two-sided alternative is specified.