A study was conducted to determine if gender was associated with undergraduate major. The investigators sampled 255 college seniors at their graduation. Is there an association between gender and undergraduate major at a 5% level of significance?

By a small margin, Facebook remains the top choice of social media over all ages, with 29% using Facebook most often among those using social media sites. However, more visually oriented social networks such as Snapchat and Instagram continue to draw in younger audiences. When asked "Which one social networking brand do you use most often?" the results in the table show the top brands chosen by Americans aged 12-34 who currently use any social networking site or service. Social M edia Site Faceboo k Snapchat Instagra m Twitter Percentage That Use Most Often 29 28 26 6 20 (a) What is the sum of the percentages for these top social media sites? Give your answer as an exact number. Macmillan Learning top social media sites: What percent of Americans aged 12-34 use other social media sites most often? Give your answer as an exact number. other social media sites: do %

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…

). You are interested in investigating if there a difference in mean cholesterol between the four diet groups. What kind of sample and outcome is this?

The National Football League (NFL) is conducting a survey of fan behavior by collecting a random sample of 240 NFL fans. One question asks fans if they have ever participated in a violent act in or around their favorite team's stadium. Nationally, 28% of NFL fans have participated in a violent act around their team’s stadium. The research finds that 14% of Green Bay Packers fans have committed a violent act on game day. Conduct a significance test to answer the research question: Is there a significant difference (a=.05) in the proportion of Green Bay Packers fans compared to the rest of the NFL fans that have participated in a violent act?    Which of the following test requirements does NOT belong in Step One for this test?  Random sample Interval ratio variable of violent acts Normal Sampling distribution What is the critical score? What is the obtained score?

5. In the United States, there is a strong relationship between education and smoking: well-educated people are less likely to smoke. Does a similar relationship hold in France? To find out, researchers recorded the level of education and smoking status of a random sample of 459 French men aged 20 to 60 years.36 The two-way table below displays the data. Is there convincing evidence of an association between smoking status and educational level among French men aged 20 to 60 years? Smoking Status Nonsmoker Former Moderate Heavy Primary School 56 54 41 36 Education Secondary School 37 43 27 32 University 53 28 36 16

Explain if there was a statistically significant difference between the group means. did you arrive at your conclusion?

In the NFL, Coaches can throw "challenge" flags if they believe officials have made an incorrect call on the field. Then, based upon further analysis, the call is either overturned (because the referees were incorrect) or upheld (referees were correct). In the first eight weeks of last NFL season, there were 316 challenges made, with 154 of those calls overturned. The NFL team owners used this data to begin a lawsuit that claimed referees were wrong more than 50% of the time in challenged situations. They want to perform statistical analysis before filing that lawsuit. For the following question, select the answer which correctly responds. 0.50

The researchers hypothesised that people who receive an audiovisual presentation will have a different mean level of recall of ad information as those who receive only the visual aspects of the ad. What significance test should the researchers use for testing their hypothesis?

The results of a random sample of students by type of school and their attitudes on safety steps taken by the school staff are shown in the table below.  At the 5% significance level, can you conclude that attitudes about safety steps taken by the school staff are related to the type of school?    School staff has  School Type  Taken all steps for  student safety  Taken some steps for  student safety  Public  40  51  Private  64  34