Spam: A researcher reported that 71.8% of all email sent in a recent month was spam. A system manager at a large corporation believes that the percentageat his company may be 78%. He examines a random sample of 500 emails received at an email server, and finds that 369 of the messages are spam. Can youconclude that less than 78% of emails are spam? Use both a = 0.10 and a = 0.01 levels of significance and the critical value method with the table.Part 1 of 5State the appropriate null and alternate hypotheses.Ho: p = 0.78H: p < 0.78This hypothesis test is a left-tailedv test.Part: 1/5Part 2 of 5Find the critical values. Round the answers to three decimal places.For a = 0.10, the critical value isFor a = 0.01, the critical value is

Answered: Image /qna-images/answer/b6dfc64d-d1c1-4d6f-8d1f-89a5fa25578d.jpg

Answered: Spam: A researcher reported that 71.8%…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

In 1990, 58% of Americans 18 years old and older reported they have a great deal of concern regarding air pollution. A recent poll found that 592 of 1004 Americans 18 years old or older stated that they have a great deal of concern regarding the level of air pollution in American. Is there evidence to conclude that the current proportion of Americans having a great deal of concern about the level of air pollution in America is different from the 1990 proportion, with a 10% level of significance? State the null hypothesis, alternative hypothesis, test statistic, p-value and conclusion.
A sample survey by Comcast asked a random sample of customers about use of the Internet and about the type of community they lived in. Here are the results: Internet Users: Rural: 433 Suburban: 1072 Urban: 536 Nonusers: Rural: 463 Suburban: 627 Urban: 388 Is there a relationship between Internet use and community type? Give statistical evidence to support your findings.
A researcher is interested in exploring the relationship between calcium intake and weight loss. Two different groups, each with 2626 dieters, are chosen for the study. Group A is required to follow a specific diet and exercise regimen, and also take a 500-mg supplement of calcium each day. Group B is required to follow the same diet and exercise regimen, but with no supplemental calcium. After six months on the program, the members of Group A had lost a mean of 10.4 pounds with a standard deviation of 2.6 pounds. The members of Group B had lost a mean of 11.7pounds with a standard deviation of 2.8 pounds during the same time period. Assume that the population variances are not the same. Construct a 99% confidence interval to estimate the true difference between the mean amounts of weight lost by dieters who supplement with calcium and those who do not. Let Population 1 be the amount of weight lost by Group A, who took a 500-mg supplement of calcium each day, and let Population 2 be…
A graduate student is interested in how viewing different types of scenes affects working memory. For his study, he selects a random sample of 36 adults. The subjects complete a series of working memory tests before and after walking in an urban setting. Before the walk, the mean score on the test of working memory was 9.1. After the walk, the mean score was 1.4 higher. The graduate student has no presupposed assumptions about how viewing different types of scenes affects working memory, so he formulates the null and alternative hypotheses as: H00 : μDD = 0 H11 : μDD ≠ 0 Assume that the data satisfy all of the required assumptions for a repeated-measures t test. The graduate student calculates the following statistics for his hypothesis test: Mean difference (MDD) 1.4 Estimated population standard deviation of the differences (s) 1.6 Estimated standard error of the mean differences (sMDMD) 0.2667 Degrees of freedom (df) 35 The t statistic 5.25 The critical values of t…
Kris works for the MESA Air Pollution Study at UW, and studies the correlation be- tween air pollution and the disease atherosclerosis. Nationally, 40% of adults suffer from atherosclerosis. Kris suspects that the proportion of people with atherosclerosis in high- pollution areas is higher. In a random sample of 600 residents of high-pollution areas, he finds that 270 (45%) subjects have atherosclerosis. At the 1% level (α = .01), is this good evidence that people in high-pollution areas are more likely to have atherosclerosis? (a) Which of the following is the Ha ? (research claim or alternate) A. Ha : p ≥ 0.40 B. Ha : pb ≥ 0.40 C. Ha : p > 0.40 D. Ha : p > b 0.40 E. Ha : p > b 0.45 F. Ha : p > 0.45 G. Ha : pb ≥ 0.45 H. Ha : p ≥ 0.45 I. None of these Hint: First read the problem and using my notes (or Hawkes) for 9.1, set up H0 and Ha . Then pick the right Ha from the above list. Dont try to guess the answer from the above list. (b) Which of the…
Computer-mediated communication (CMC) is a form of interaction that heavily involves technology (e.g., instant messaging, email). A study was conducted to compare relational intimacy in people interacting via CMC to people meeting face-to-face (FTF). Participants were 48 undergraduate students, of which half were randomly assigned to the CMC group and half assigned to the FTF group. The variable of interest, relational intimacy score, was measured (on a 7-point scale) for each participant after each of three different meeting sessions. Summary statistics for the first meeting session are given here. The researchers hypothesized that, after the first meeting, the mean relational intimacy score for participants in the CMC group would be lower than the mean relational intimacy score for participants in the FTF group. Test the researchers’ hypothesis using α = .10. CMC FTF Number…
Given are five observations for two variables, x and y. x i 1 2 3 4 5 y i 4 8 6 12 14 Round your answers to two decimal places. Estimate the standard deviation of ŷ* when x = 3. b. Using the following expression: Develop a 95% confidence interval for the expected value of y when x = 3. to c. Estimate the standard deviation of an individual value of y when x = 3. d. Develop a 95% prediction interval for y when x = 3. If your answer is negative, enter minus (-) sign.
Spam: A researcher reported that 71.8 % of all email sent in a recent month was spam. A system manager at a large corporation believes that the percentage at his company may be 69%. He examines a random sample of 500 emails received at an email server, and finds that 365 of the messages are spam. Can you conclude that greater than 69% of emails are spam? Use both a=0.01 and a= 0.05 levels of significance and the critical value method with the table. Part 1 of 5 State the appropriate null and alternate hypotheses. Ho: P- .69 H1: p> .69 This hypothesis test is a right-tailed V test. Part 2 of 5 Find the critical values. Round the answers to three decimal places. For a=0.01 , the critical value is 2.326 For a=0.05 , the critical value is 1.645 Part: 2/5 Part 3 of 5 Compute the test statistic. Do not round intermediate calculations. Round the answer to two decimal places.
Management of a theater in a large city wants to know whether its popularity increased after it ran a popular musical. According to a previous study, 25% of city residents said they had been to the theater in the past year. A more recent study, conducted after the musical had run for a year, found that 156 of 536 residents sampled said they had been to the theater in the past year. Is there evidence at the ? = 0.05 level that the number of residents who have been to the theater has increased in the last year?
Researchers asked soda drinkers to view either the logo for their favorite soda or a graphic warning demonstrating the harmful effects of sugary beverages (e.g., tooth decay, obesity) and then measured their negative mood with a short survey. They found that those participants who saw the warnings reported significantly greater negative moods than those who saw the logos. Which statistical test should be used?
The Wall Street Journal asked Concur Technologies, Inc., an expense management company, to examine data from 8.3 million expense reports to provide insights regarding business travel expenses. Their analysis of the data showed that New York was the most expensive city. The following table shows the average daily hotel room rate (*) and the average amount spent on entertainment (y) for a random sample of 9 of the 25 most-visited U.S. cities. These data lead to the estimated regression equation ŷ = 17.49 +1.0334x. For these data SSE = 1541.4. Click on the datafile logo to reference the data. Use Table 1 of Appendix B. DATA file City Boston Denver Nashville New Orleans Phoenix San Diego San Francisco San Jose Room Rate ($) 148 96 91 110 90 102 136 90 82 Tampa a. Predict the amount spent on entertainment for a particular city that has a daily room rate of $89 (to 2 decimals). $ Entertainment ($) 161 105 101 142 ***** b. Develop a 95% confidence interval for the mean amount spent on…
The personality characteristics of business leaders (e.g., CEOS) are related to the operations of the businesses that they lead (Oreg & Berson, 2018). Traits like openness to experience are related to positive financial outcomes and other traits are related to negative financial outcomes for their businesses. Suppose that a board of directors is interested in evaluating the personality of their leadership. Among a sample of n = 16 managers, the sample mean of the openness to experiences dimension of personality was M = 4.50. Assuming that u = 4.24 and o = 1.05 (Cobb-Clark & Schurer, 2012), use a two-tailed hypothesis test with a = .05 to test the hypothesis that this company's business leaders' openness to experience is different from the population. Standard Normal Distribution Mean - 0.0 Standard Deviation 1.0 .7198 .1401 .1401 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 -1.08 1.08 Step 1. Ho: ; H;: a = .05. Step 2. The critical region consists of Step 3. For these data the standard error is and…

SEE MORE QUESTIONS

Recommended textbooks for you

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

Elementary Statistics: Picturing the World (7th E…

Statistics

ISBN:

9780134683416

Author:

Ron Larson, Betsy Farber

Publisher:

PEARSON

The Basic Practice of Statistics

Statistics

ISBN:

9781319042578

Author:

David S. Moore, William I. Notz, Michael A. Fligner

Publisher:

W. H. Freeman

Introduction to the Practice of Statistics

Statistics

ISBN:

9781319013387

Author:

David S. Moore, George P. McCabe, Bruce A. Craig

Publisher:

W. H. Freeman

SEE MORE TEXTBOOKS