/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q33E The article 鈥淭he Foreman鈥檚 V... [FREE SOLUTION] | 91影视

91影视

The article 鈥淭he Foreman鈥檚 View of Quality Control鈥 (Quality Engr., 1990: 257鈥280) described an investigation into the coating weights for large pipes resulting from a galvanized coating process. Production standards call for a true average weight of 200 lb per pipe. The accompanying descriptive summary and boxplot are from Minitab.

a. What does the boxplot suggest about the status of the specification for true average coating weight?

b. A normal probability plot of the data was quite straight. Use the descriptive output to test the appropriate hypotheses.

Short Answer

Expert verified

(a) The production criteria do not appear to have been met.

(b) The true average weight is different from \(200lb\) per price is supported by appropriate evidence.

Step by step solution

01

Define p-value in hypothesis testing.

The null hypothesis states that the population mean is equal to the value mentioned in the claim. If the null hypothesis is the claim, then the alternative hypothesis states the opposite of the null hypothesis.

\(\begin{array}{l}{H_0}:\mu = 0\\{H_a}:\mu \ne 0\end{array}\)

The formula for the value of the test statistic is given by, \(t = \frac{{\bar x - {\mu _0}}}{{s/\sqrt n }}\).

02

Determine the status of the specification for true average coating weight.

The given true average weight is \(200lb\) per price. Let the given boxplot be:

Because the majority of the boxplot lies to the right (and thus above) the \(200lb\) specification, the production criteria do not appear to have been met.

03

Test the appropriate hypotheses.

Let the given be:

\(\begin{array}{c}n = 30\\\mathop x\limits^\_ = 206.73\\s = 6.35\end{array}\)

Assume: \(\alpha = 0.05\).Claim that the average is equal to \(200lb\) per price. The given claim is either the null hypothesis or the alternative hypothesis.

The value of the test statistic:

\(\begin{array}{c}t = \frac{{\bar x - {\mu _0}}}{{s/\sqrt n }}\\ = \frac{{206.73 - 200}}{{6.35/\sqrt {30} }}\\ \approx 5.805\end{array}\)

The P-value is the chance of getting the test statistic's result, or a number that is more severe. The P-value is the number (or interval) in the column header of the T table in the appendix that contains the t-value in the row \(\begin{array}{c}df = n - 1\\ = 30 - 1\\ = 29\end{array}\) for the student.

\(P < 2 \times 0.0005 = 0.001\)

As the P-value is smaller than the significance level, so the null hypothesis is rejected.

\(P < 0.05 \Rightarrow {\rm{Reject }}{H_0}\)

The true average weight is different from \(200lb\) per price is supported by appropriate evidence.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

In Problems \(31 - 34\) find values of m so that the function \(y = m{e^{mx}}\) is a solution of the given differential equation.

\(y' + 2y = 0\)

The calibration of a scale is to be checked by weighing a 10-kg test specimen 25 times. Suppose that the results of different weightings are independent of one another and that the weight on each trial is normally distributed with 蟽 = .200 kg. Let 碌 denote the true average weight reading

on the scale.

a.What hypotheses should be tested?

b.With the sample mean itself as the test statistic, what is the P-value when \(\overline x = 9.85\), and what would you conclude at significance level .01?

c.For a test with 伪 =.01, what is the probability that recalibration is judged unnecessary when in fact 碌=10.1? When 碌= 9.8?

Newly purchased tires of a particular type are supposed to be filled to a pressure of 30 psi. Let 碌 denote the true average pressure. A test is to be carried out to decide whether 碌 differs from the target value. Determine the P-value for each of the following z test statistic values.

a.2.10 b. -1.75 c. -.55 d. 1.41 e. -5.3

The paint used to make lines on roads must reflect enough light to be clearly visible at night. Let \(\mu \) denote the true average reflectometer reading for a new type of paint under consideration. A test of \({H_0}:\mu = 20\) versus \({H_n}:\mu > 20\) will be based on a random sample of size n from a normal population distribution. What conclusion is appropriate in each of the following situations?

\(\begin{array}{l}a.n = 15,t = 3.2,\alpha = .05\\b.n = 9,t = 1.8,\alpha = .01\\c.n = 24,t = - 2\end{array}\)

To determine whether the pipe welds in a nuclear power plant meet specifications, a random sample of welds is selected, and tests are conducted on each weld in the sample. Weld strength is measured as the force required to break the weld. Suppose the specifications state that mean strength of welds should exceed 100 lb/in2 ; the inspection team decides to test H0: 碌= 100 versus Ha: 碌> 100. Explain why it might be preferable to use

this Ha rather than 碌 < 100.

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.