Questions from Statistics

Q: The scatterplot in Figure 7.18 depicts paired data values consisting

The scatterplot in Figure 7.18 depicts paired data values consisting of the weight (in grams) and year of manufacture for each of 72 pennies. a. Considering the complete collection of data, does there...

Q: Briefly explain how an outlier can make it appear that there is

Briefly explain how an outlier can make it appear that there is correlation when there is none. Also briefly explain how an outlier can make it appear that there is no correlation when there is one. U...

Q: Briefly explain how data that actually come from two distinct groups,

Briefly explain how data that actually come from two distinct groups, both with strong correlations, can appear uncorrelated when grouped together. Does this mean that you should always break data int...

Q: What are the three possible explanations for a correlation?

What are the three possible explanations for a correlation?

Q: If a correlation is very strong, can we conclude that one

If a correlation is very strong, can we conclude that one variable causes a change in the other variable? Why or why not?

Q: I used a best-fit line for data showing the ages

I used a best-fit line for data showing the ages and heights of thousands of boys of various ages to predict the mean height of 9-year-old boys.

Q: The data barely deviate at all from the best-fit line

The data barely deviate at all from the best-fit line, and they produce this value for the square of the correlation coefficient: r2 = 0.3.

Q: Using sample data on footprint lengths and heights from men, the

Using sample data on footprint lengths and heights from men, the equation of the best-fit line is obtained, and it is used to find that a man with a footprint length of 36 inches is predicted to have...

Q: In seeking to understand the factors that affect a college graduate’s future

In seeking to understand the factors that affect a college graduate’s future income, researchers conducted a multiple regression analysis that examined the effects of major, grade point average, the r...

Q: In each case, answer the following. a. How

In each case, answer the following. a. How well does the best-fit line actually fit the points in the scatterplot? b. Briefly discuss the strength of the correlation. Estimate or compute r and r2. Bas...