Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 26.3 with a standard deviation of 5.2, while the 200 students in group 2 had a mean score of 17.6 with a standard deviation of 2.8. Complete parts (a) and (b) below. (a) Determine the 90% confidence interval for the difference in scores, u, -H2. Interpret the interval. The lower bound is The upper bound is (Round to three decimal places as needed.)

A high school teacher would like to examine his students’ exam scores based on seating arrangements. He assigned n = 15 students to sit in the last three rows of his class and n = 15 students to sit in the first three rows. Each student received a 45-minute lecture for one week and were given the same exam the following school day. The front row students had a mean of M = 78 with SS = 10.50 on their exam. And the back row students had a mean of M = 72 with SS = 8.90. Is there a significant difference in exam scores? Test with  = .05.

4. At private college the achievement test is used for advanced study placement. Counselors selected a random sample of 144 students from the college and scored their tests by hand before sending them in for computer processing. For this sample, the mean was 450 and s = 29. Construct a 98% confidence interval for the mean.

In a poll, 1100 adults in Nantucket were asked about their computer gaming habits. One finding was that 43% of respondents never computer game. Find and interpret a 95% confidence interval for the proportion of all adults in Nantucket who never play computer games

At one large college, 660 out of the 1500 students surveyed said they plan to take another science class.Find the 95% confidence interval for the proportion of students that said they plan to take another science class.

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.

Customers of a restaurant have been complaining about food poisoning over the past week. A health professional was called to investigate. He tested a representative sample of the eggs and reported that  23%  of the sample eggs tested positive for the salmonella bacterium. If a second health professional tests 4 eggs at random, what is the mean of the number of eggs that test positive for salmonella?

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 State Transportation Department is thinking of changing its speed limit signs. It is considering two new options in addition to the existing sign design. At question is whether the three sign designs will produce the same mean speed. To test this, the department has conducted a limited test in which a stretch of roadway was selected. With the original signs up, a random sample of 30 cars was selected and the speeds were measured. Then, on different days, the two new designs were installed, 30 cars each day were sampled, and their speeds were recorded. Suppose that the following summary statistics were computed based on the data. X₁ = 62.1 X₂ = 58.94 X3 = 71.2 SST = 6016 Based on these sample results and significance level equal to 0.05, what is the sum of squares between?

A nationwide job recruiting firm wants to compare the annual incomes for childcare workers in Connecticut and California. Due to recent trends in the childcare industry, the firm suspects that the that the mean annual income of childcare workers in the state of Connecticut is greater than the mean annual income of childcare workers in California. To see if this is true, the firm selected a random sample of 10 childcare workers from Connecticut and an independent random sample of 10 childcare workers from California and asked them to report their mean annual income. The data obtained were as follows. 80°F Partly sunny Annual income in dollars Connecticut 42438, 52287, 46837, 49334, 52848, 52929, 57111, 51860, 44967, 52174 California 50998, 38334, 56804, 50919, 49446, 41141, 45717, 43963, 55156, 47295 LL D 144Hz Send data to calculator V The population standard deviations for the annual incomes of childcare workers in Connecticut and in California are estimated as 6300 and 6100,…