Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Lobster trap placement. Refer to the Bulletin of Marine Science (April 2010) observational study of lobster trap placement by teams fishing for the red spiny lobster in Baja California Sur, Mexico, Exercise 6.29 (p. 348). Trap-spacing measurements (in meters) for a sample of seven teams of red spiny lobster fishermen are reproduced in the accompanying table. Let \(\mu \) represent the average of the trap-spacing measurements for the population of red spiny lobster fishermen fishing in Baja California Sur, Mexico. In Exercise 6.29 you computed the mean and standard deviation of the sample measurements to be \(\bar x = 89.9\) meters and s = 11.6 meters, respectively. Suppose you want to determine if the true value of \(\mu \) differs from 95 meters

a. Specify the null and alternative hypotheses for this test.

Short Answer

Expert verified

a)

\(\begin{array}{}{H_0}:\mu = 95\\{H_a}:\mu \ne 95\end{array}\)

Step by step solution

01

Given Information

The sample size is 7.

The mean and standard deviation is given. i.e.

\(\bar x = 89.9\,and\,s = 11.6\)

02

Standard deviation

The standard deviation is a metric that calculates as the sum of squares of the variance as well as quantifies the dispersion of a data compared to its mean. The standard deviation is determined as the sum of squares of the variance by calculating the departure of each piece of data from the mean.In descriptive statistics, the standard deviation is the amount of dispersal as well as scattering of sample points compared to their mean.

03

Step 3:

The hypothesis is given by

\(\begin{array}{}{H_0}:\mu = 95\\{H_a}:\mu \ne 95\end{array}\)

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 Vaia!

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

Question: Testing the placebo effect. The placebo effect describes the phenomenon of improvement in the condition of a patient taking a placeboโ€”a pill that looks and tastes real but contains no medically active chemicals. Physicians at a clinic in La Jolla, California, gave what they thought were drugs to 7,000 asthma, ulcer, and herpes patients. Although the doctors later learned that the drugs were really placebos, 70% of the patients reported an improved condition. Use this information to test (at ฮฑ = 0.05) the placebo effect at the clinic. Assume that if the placebo is ineffective, the probability of a patientโ€™s condition improving is 0.5.

For safety reasons, calf dehorning has become a routine practice at dairy farms. A report by Europeโ€™s Standing Committee on the Food Chain and Animal Health (SANKO) stated that 80% of European dairy farms carry out calf dehorning. A later study, published in the Journal of Dairy Science (Vol. 94,2011), found that in a sample of 639 Italian dairy farms, 515 dehorned calves. Does the Journal of Dairy Science study support or refute the figure reported by SANKO? Explain.

Factors that inhibit learning in marketing. What factors inhibit the learning process in the classroom? To answer this question, researchers at Murray State University surveyed 40 students from a senior-level marketing class (Marketing Education Review). Each student was given a list of factors and asked to rate the extent to which each factor inhibited the learning process in courses offered in their department. A 7-point rating scale was used, where 1 = โ€œnot at allโ€ and 7 = โ€œto a great extent.โ€ The factor with the highest rating was instructor related: โ€œProfessors who place too much emphasis on a single right answer rather than overall thinking and creative ideas.โ€ Summary statistics for the student ratings of this factor are\(\overline x = 4.70\),\(s = 1.62\)

a. Conduct a test to determine if the true mean rating for this instructor-related factor exceeds 4. Use\(\alpha = 0.05\).Interpret the test results.

b. Examine the results of the study from a practical view, and then discuss why โ€œstatistically significantโ€ does not always imply โ€œpractically significant.โ€

c. Because the variable of interest, rating, is measured on a 7-point scale, it is unlikely that the population of ratings will be normally distributed. Consequently, some analysts may perceive the test, part a, to be invalid and search for alternative methods of analysis. Defend or refute this argument

If you test a hypothesis and reject the null hypothesis in favor of the alternative hypothesis, does your test prove that the alternative hypothesis is correct? Explain.

Corporate sustainability of CPA firms. Refer to the Business and Society (March 2011) study on the sustainability behaviors of CPA corporations, Exercise 6.12 (p. 339). Recall that the level of support for corporate sustainability (measured on a quantitative scale ranging from 0 to 160 points) was obtained for each in a sample of 992 senior managers at CPA firms.

The data (where higher point values indicate a higher level of support for sustainability) are saved in the accompanying file. The CEO of a

CPA firm claims that the true mean level of support for sustainability is 75 points.

a. Specify the null and alternative hypotheses for testing this claim.

b. For this problem, what is a Type I error? A Type II error?

c. The XLSTAT printout shown above gives the results of the test. Locate the test statistic and p-value on the printout.

d. At ฮฑ = .05, give the appropriate conclusion.

e. What assumptions, if any, about the distribution of support levels must hold true in order for the inference derived from the test to be valid? Explain.

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.

Sign-up for free