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 78%. He examines a random sample of 500 emails received at an email server, and finds that 369 of the messages are spam. Can you conclude that less than 78% of emails are spam? Use both a = 0.10 and a = 0.01 levels of significance and the P-value method and Excel. (a) State the appropriate null and alternate hypotheses. Ho: H₁: This hypothesis test is a (Choose one) ▼ test. right tailed left tailed two tailed

Suppose that in a random selection of 100 colored​ candies, 23​% of them are blue. The candy company claims that the percentage of blue candies is equal to 26​%. Use a 0.05 significance level to test that claim.

What social media tools do marketers commonly​ use? Researchers surveyed marketers who commonly use an indicated social media tool. Surveyed were B2B​ marketers, marketers focusing primarily on attracting businesses, and B2C marketers, marketers targeting consumers. Suppose the survey was based on 500 B2B and 500 B2C marketers and yielded the results in the table below. For each social media​ tool, at the 0.05 level of​ significance, determine whether there is a difference between B2B marketers and B2C marketers in the proportion who used each social media tool. Social Media Tool    B2B    B2CA                                84%    91%B                                84%    76%C                                82 %   61%D                                39%    53% What is the​ p-value for the test​ statistic and interpretation? For Tool B determine the test statistic. What is Tool B p-value    12. EOC

A statistics content developer at Aplia wanted to know whether study skills are related to memory quality. She invited student volunteers to perform an online memory task. The students saw a list of 60 words and were then asked to recognize a list of 10 words that were on the original list. Students were also asked to provide their GPAs.   Consider the following data set, which was collected from student volunteers in 2009. The table gives the frequency for five intervals of scores on the number of correctly identified words. Use the dropdown menus to complete the table by filling in the missing values for the proportions and percentages. Score Interval f Proportion Percentage 9–10 29 0.19 19% 7–8 53           5–6 50           3–4 22 0.14 14% 1–2 1 0.01 1%

The National Football League (NFL) records a variety of performance data for individuals and teams. To investigate the importance of passing on the percentage of games won by a team, the following data show the average number of passing yards per attempt (Yds/Att) and the percentage of games won (WinPct) for a random sample of 10 NFL teams for the 2011 season (NFL website). Team Yds/Att WinPct 5.7 26 Arizona Cardinals Atlanta Falcons Carolina Panthers 7.6 67 7.3 52 6.9 51 Chicago Bears Dallas Cowboys 5.1 17 8.6 82 New England Patriots Philadelphia Eagles Seattle Seahawks 5.3 21 6.6 41 St. Louis Rams 6.5 41 Tampa Bay Buccaneers. 6.1 38 a. Choose the correct a scatter diagram with the number of passing yards per attempt on the horizontal axis and the percentage of games won on the vertical axis. B. A. WinPct WinPct 80 DD J F1 70- 60- 50+ -40- 30 20- F2 80 F3 000 000 F4 F5 80- -70 60- 50- 40- 30- 20- S F6 ● - F7 DII F8 F9 F10 () F11 <))) F12 A

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…

What percentage of Contra Costa County adults supports a ban on assault-style weapons? Suppose that we survey a random sample of 100 adults living in Contra Costa County and find that 62% support a ban on assault-style weapons. According to  a  2015 study by  the Pew  Research Center, 57% of U.S.  adults  favor a ban on assault-style weapons. Assuming that the variability in random samples will be the same in Contra Costa County as in the U.S., find the 95% confidence interval to estimate the proportion of CCC adults that favor a ban on assault-style weapons.   g. Are we confident that the percentage of Contra Costa County residents that supports a ban is greater than the percentage nationwide as reported by the Pew Research Center? Why or why not?

A company claims that less than 30% of people who both work and live in Newcastle. A study revealed that among a random sample of 200 people working in Newcastle, 62 also lived in Newcastle. Does the sample support the company’s claim? Use a level of significance of 0.01.

A study was conducted to explore the possibility of a audiobook treatment effect on sleep quality (better, worse). One version of the study involved 32 uber drivers. The uber drivers were given the option to choose which group they were in. One group listened to an audiobook while they slept, while the other group did not. The researchers found a difference of 21.9 percentage points between the proportion of uber drivers in each group who experienced better sleep quality. The group that listened to an audiobook had the higher proportion. The tail proportion from a randomisation test carried out with the data from the study was 1/1000.