​A chi-square test for goodness of fit is used to examine the distribution of individuals across three categories, and a chi-square test for independence is used to examine the distribution of individuals in a 2×3 matrix of categories. Which test has the larger value for df?   Question  options: a ​The test for independence b ​The test for goodness of fit c ​Both tests have the same df. d ​The df value depends on the sizes of the samples that are used.

Please be advised these are practice exam questions.

2. Which of the two methods is better?  Support your answer. The other method is Least Squares Method.

In a computer game, different units are created randomly with different levels of range and Aggression according to the table below. Range is how far the unit can attack without moving, and Aggression is used to determine how far a unit will move to attack without direct command.       Range   Total     1 2 4     5 0.2 0.15 0 0.35 Aggression 3 0.1 0.15 0.1 0.35   0 0 0.05 0.25 0.3 Total   0.3 0.35 0.35 1 Calculate the Expected value of aggression for the units created. (E(Aggression))

Dataset: NES. Variables: spend8, nesw.) The NES dataset contains spend8, which records the number of government policy areas where respondents think spending should be increased. Scores range from 0 (the respondent does not want to increase spending on any of the policies) to 8 (the respondent wants to increase spending on all eight policies). The NES, of course, polls a random sample of U.S. adults. In this exercise you will analyze spend8 using the Analyze ▶ Compare Means ▶ One-Sample T Test procedure. You then will draw inferences about the population mean. Make sure you weight observations using the nesw variable so your results are nationally representative.   A. The spend8 variable has a sample mean of ______.

The medical researcher is comparing two treatments for lowering cholesterol: diet and meds. The researcher wants to see if the patients who receive the recommendation to change their diet have less success lowering cholesterol compared to a prescription of meds. A random sample of some patients who received the recommendation to change their diet and others who were prescribed meds was taken. The results of how many did or did not lower their cholesterol are shown below: Data on Diet vs. Meds for Weight Los Diet Meds Yes 416 483 No 266 248 What can be concluded at the a = 0.05 level of significance? %3D For this study, we should use Select an answer a. The null and alternative hypotheses would be: Ho: Select an answer > Select an answer Select an answer O (please enter a decimal) Hj: Select an answer Select an answer Select an answer O (Please enter a decimal) b. The test statistic ? O (please show your answer to 3 decimal places.) c. The p-value = (Please show your answer to %3D 4…

A test is being designed to compare the wearing quality of two brands of tires, say brand A and brand B. Six automobiles will be selected and equipped with the new tires from both brands and driven under normal conditions for 1 month. A measurement will be taken to determine how much wear took place on a scale from 0 to 200. Below is a table of the paired data collected from the 6 cars in the test. [BrandA BrandB] 125 64 64 65 94 103 38 37 90 102 106 115 Conduct a hypothesis test to determine whether the mean of the difference population is 0 at a significance level of a =. State your conclusion.

PETROGAS is testing new filters for its motorbikes. One brand of filter (Filter A) is placed in one motorbike, and the other brand (Filter B) is placed in the second motorbike. Random samples of air released from the motorbikes are taken at different times throughout the day. Pollutant concentrations are measured for both motorbikes at the same time. The following data attached represent the pollutant concentrations (in parts per million) for samples taken at 20 different times after passing through the filters. a. Test the hypothesis that the mean for the pollutant concentration for Filter B is greater than 30. Use the 1% level of significance. b. Construct a 95% confidence interval for the difference in mean pollutant concentration, where a difference is equal to the pollutant concentration passing through Filter A minus the passing through Filter B. c. Using the 5% significance level, determine whether there is evidence that mean for the pollutant concentration for Filter A…

Refer to the sample data for pre-employment drug screening shown below. If one of the subjects is randomly selected, what is the probability that the test result is a false positive? Who would suffer from a false positive result? Why? Positive test result Negative test result Drug Use Is Indicated Drug Use Is Not Indicated Subject Uses Drugs 39 14 Subject Is Not a Drug User 2 36 Pre-Employment Drug Screening Results The probability of a false positive test result is (Round to three decimal places as needed.)