12.6 Outliers

Using this new line of best fit (based on the remaining ten data points in the third exam/final exam example), what would a student who receives a 73 on the third exam expect to receive on the final exam? Is this the same as the prediction made using the original line?

Do there appear to be any outliers?

What effect did the potential outlier have on the line of best fit?

The Sum of Squared Errors for a data set of 18 numbers is 49. What is the standard deviation?

Ornithologists, scientists who study birds, tag sparrow hawks in 13 different colonies to study their population. They gather data for the percent of new sparrow hawks in each colony and the percent of those that have returned from migration.

Percent return:74; 66; 81; 52; 73; 62; 52; 45; 62; 46; 60; 46; 38
Percent new:5; 6; 8; 11; 12; 15; 16; 17; 18; 18; 19; 20; 20

1. Enter the data into your calcu…

The following table consists of one student athlete’s time (in minutes) to swim 2000 yards and the student’s heart rate (beats per minute) after swimming on a random sample of 10 days:

1. Enter the data into your calculator and make a scatter plot.
2. Use your calculator’s regression function to find the equation of the least-squares regression line. Add this to your scatter plot from part a.
3. Explain…

Using the data to determine the linear-regression line equation with the outliers removed. Is there a linear correlation for the data set with outliers removed? Justify your answer.

The percent of women who are wage and salary workers who are paid hourly rates is given in the table for a 14-year period.

1. Using “year” as the independent variable and “percent” as the dependent variable, draw a scatter plot of the data.
2. Does it appear from inspection that there is a relationship between the variables? Why or why not?
3. Calculate the least-squares line. Put the equation in the form…

1. Complete the table for the cost per ounce of the different sizes.
2. Using “size” as the independent variable and “cost per ounce” as the dependent variable, draw a scatter plot of the data.
3. Does it appear from inspection that there is a relationship between the variables? Why or why not?
4. Calculate the least-squares line. Put the equation in the form of: ŷ = a + bx
5. Find the correlation coefficient.…

The following are advertised sale prices of hard disk drives on Amazon’s website for various capacity hard drives.

1. Decide which variable should be the independent variable and which should be the dependent variable.
2. Draw a scatter plot of the data.
3. Does it appear from inspection that there is a relationship between the variables? Why or why not?
4. Calculate the least-squares line. Put the equation…

We are interested in whether there is a relationship between the ranking of a state and the area of the state.

1. What are the independent and dependent variables?
2. What do you think the scatter plot will look like? Make a scatter plot of the data.
3. Does it appear from inspection that there is a relationship between the variables? Why or why not?
4. Calculate the least-squares line. Put the equation in…