Questions from Essentials of Statistics

Q: The U.S. Congress, Joint Committee on Printing,

The U.S. Congress, Joint Committee on Printing, provides information on the composition of Congress in Congressional Directory. On the WeissStats site, we present data on party and class for the senat...

Q: Use Table V to find the required χ2-values. Illustrate

Use Table V to find the required χ2-values. Illustrate your work graphically. For a χ2-curve with 22 degrees of freedom, determine the χ2-value that has area a. 0.01 to its right. b. 0.005 to its rig...

Q: In this exercise, you are to consider two variables, x

In this exercise, you are to consider two variables, x and y, defined on a hypothetical population. Following are the conditional distributions of the variable y corresponding to each value of the var...

Q: The U.S. Census Bureau publishes census data on the

The U.S. Census Bureau publishes census data on the resident population of the United States in Current Population Survey. According to that document, 7.3% of male residents are in the age group 20–24...

Q: To decide whether two variables of a population are associated, we

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?

Q: Step 1 of Procedure 12.2 gives generic statements for the

Step 1 of Procedure 12.2 gives generic statements for the null and alternative hypotheses of a chi-square independence test. Use the terms statistically dependent and statistically independent, introd...

Q: If no association exists between marital status and alcohol consumption, the

If no association exists between marital status and alcohol consumption, the proportion of married adults who abstain is the same as the proportion of all adults who abstain. Explain why that statemen...

Q: A chi-square independence test is to be conducted to decide

A chi-square independence test is to be conducted to decide whether an association exists between two variables of a population. One variable has six possible values, and the other variable has four....

Q: In the article, “One’s Sex, Sleep, and Posttraumatic

In the article, “One’s Sex, Sleep, and Posttraumatic Stress Disorder” (Biology of Sex Differences, Vol. 3, No. 29, pp. 1–7), I. Kobayashi et al. study the relationship between one’s sex, sleep pattern...

Q: From the Baseball Almanac website, we found the heights, in

From the Baseball Almanac website, we found the heights, in inches, of the players on the 2012 World Series–winning San Francisco Giants baseball team. a. Construct a stem-and-leaf diagram of these da...