To decide whether two variables of a population are associated, we usually need to resort to inferential methods such as the chi-square independence test. Why?

Researchers wondered if there was a difference between males and females in regard to some common annoyances. They asked a random sample of males and females, the following question: "Are you annoyed by people who repeatedly check their mobile phones while having an in-person conversation?" Among the 505 males surveyed, 171 responded "Yes"; among the 522 females surveyed, 202 responded "Yes." Does the evidence suggest a higher proportion of females are annoyed by this behavior? Complete parts (a) through (g) below. H₁: P₁ P2 (d) Describe the sampling distribution of Pfemale Pmale Draw a normal model with the area representing the P-value shaded for this hypothesis test. The sampling distribution is approximately normal with mean and standard deviation (Type an integer or decimal rounded to four decimal places as needed.)

Please explain:   What kind of a study can be measured by an independent samples t-test?   What kind of a study can be measured by a dependent (paired) samples t-test?    Give an example of a null hypothesis for an independent samples t-test:   Give an example of a null hypothesis for a dependent (paired) samples t-test:

A fitness course claims that it can improve an individual's physical ability. To test the effect of a physical fitness course on one's physical ability, the number of sit-ups that a person could do in one minute, both before and after the course, was recorded. Ten individuals are randomly selected to participate in the course. The results are displayed in the following table. Can it be concluded, from the data, that participation in the physical fitness course resulted in significant improvement? Let d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course)d=(number of sit-ups that can be done after taking the course)−(number of sit-ups that can be done prior to taking the course). Use a significance level of α=0.01α=0.01 for the test. Assume that the numbers of sit-ups are normally distributed for the population both before and after taking the fitness course. Sit-ups before 2121 2424 4141 5252 5151 2626 2121 4141…

What are the response variables and explanatory variables for observing vehicles to see what the cars do as they approach a stop sign during rush hour on a local street?

If the data have come from independent samples then it doesn’t matter which variable we assign to variable 1 and which we assign to variable 2 in the following null hypothesis: H0: The distribution of variable 1 is the same for each level of variable 2. Group of answer choices True False

A bivariate table is one in which a. a dependent variable is cross-classified by two or more independent variables b. a single variable is broken down into two categories c. there are two rows and two columns d. a dependent variable is cross-classified by an independent variable

A physical therapist believes that men have higher blood pressure than women. He collected the blood pressure samples from 21 men and 21 women.Male: Mean: 106 Std. Dev: 10 N = 21 Female: Mean: 108 Std. Dev: 6 N = 21 A). What is the type of test you will use? (z-test, single-sample t-test, paired-samples t-test, or independent samples t-test) and why (what information provided in the problem) B). What are the hypotheses (Be Specific)

A researcher is interested in studying the effects of altitude on cognitive performance (e.g., perception, memory, problem solving, etc.). The researcher finds a group of experienced mountain climbers (n = 10) who volunteer to participate in the study. All of the climbers are tested at three different altitudes—at sea level (in the researchers’ laboratory at the University of California, San Diego), at the base camp (9,000 feet above sea level), and at 23,000 feet above sea level (at the peak of Mt. Denali in Alaska). At each location, the climbers perform a memory task (remember a list of 16 non-words like “biv”), and the accuracy of their memory is recorded (i.e., # of correctly recalled words). a. pls name the independent variable, dependent variable, levels of the IV, and the type of experiment design of this study (i.e., b/w- or w/i-subject design ) b. on what level of measurement is accuracy of memory assessed? (i.e., is it on nominal, ordinal, interval, or ratio?

A researcher is examining whether two variables, A and B, are independent or not. Variables A and B have 5 and 6 categories, respectively. A sample of n = 400 subjects is obtained. What is the degrees of freedom in the chi-squared test?