An environmentalist wishes to conduct a hypothesis test on the percentage of cars driven in the city that are hybrids. Is it sufficient for him to use a simple random sample of 152 cars if hybrids currently account for 7 % of the car sales in the country and he claims that the percentage of hybrids in the city is higher than that? Answer E Tables E Keypad Keyboard Shortcu O Yes O No

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.

The Bureau of Labor Statistics reports that the official unemployment rate for Black people was 10.4% and 4.7% for White people in February 2015. Select all correct answers for this question. O The samples of white and black people are independent. The explanatory variable is the unemployment rate. The response variable is the unemployment rate. The response variable is race.

A scientist studied the spread of AIDS and concluded that 24% of people contracted the disease. There is a problem with this conclusion. What should the correct conclusion state?

One study found a negative correlation between participant’s age and hours of sleep they got (as they got older, they slept less). Which additional fact would lead you to believe that the relationship between age and hours of sleep is one of causation and not correlation?     Jim is 63 and sleeps more than he did when he 47.     Josie is 40 and sleeps fewer hours than when she was 30.     The participants were randomly selected, the sample size was large, and the participants did not know the goal of the study.     Jennie sometimes has difficulty sleeping.

A researcher gathered a sample of participants who volunteered for a studying of phobias. She measured anxiety level of participants as they viewed photos of spiders and again when they viewed puppies. Which statistical test is appropriate for this study and why?

The city council is considering a law that would ban smoking in all public facilities. A sample has been selected from the community and tested for support of the ordinance. Is there a statistically significant relationship between age and support for the anti-smoking law? Use the five step model as a guide and write a sentence or two interpreting your results.                        Age   Less than 40 More than 40   Support:       For 145   78 223   Against 103 169 272     248 247 495

Many people like to play app based games on their mobile devices. Suppose we would like to estimate the average amount of time (in hours) per week students have played an app-based game on their mobile device at CSU Stan. In order to do this, we take a random sample of 20 students and ask them how many hours they have played an app- based game in the last week. The following data were collected: 11 4 5.5 5.5 7 6.2 10 10 7.5 6 7 7.5 2.5 Which of the following is the correct 99% confidence interval for the estimate of the average number of hours (per week) that all CSU Stan students have played an app- based game? [5.28, 7.59] [4.86, 8.01] [5.48,7.39] [5.86, 7.01]

A political scientist claims that 38% of first-year college students characterize themselves as being “moderate” or “middle of the road” as far as their political affiliation is concerned.   Believing this claimed value is too high, you survey a random sample of 400 first-year college students and find that 120 characterize themselves as being “moderate” or “middle of the road.”    Based on this information, what will the test statistic be? Choose the answer below that is closest to what you calculate, and try not to do a lot of rounding until you get to the very end of your calculations.   1. -0.3 2. -1.2 3. -2.6 4. -3.3 5. None of the other answer options are correct because the test statistic should be positive, not negative.

A district health officer wishes to determine if the six villages in his district are independent of residents contracting malaria, schistosomiasis, cholera or tuberculosis. Identity an appropriate statistical test and the tail of the test for the problem. Assume all samples used for study come from a normal population.