Chapter 6 Review: Bivariate Data Analysis

Blood pressure levels for women increase as they get older. What is the best description for the association between blood pressure levels and a woman’s age?

• Positive Correlation

• Zero correlation

• Negative correlation

• Constant correlation

What is the correlation between the variables in the scatterplot?

• Strong positive

• Weak positive

• Strong negative

• Weak negative

Which of the following scatterplots shows weak negative correlation?

• 
• 
• 
• 

The birth weight and weight at age 21 of eight women are given in the table above.

What is the value of Pearson’s correlation coefficient?

• 0.5360

• 0.6182

• 0.7863

• 0.8232

Answer explanation

It should take a maximum of 1.5 minutes to type the data into the calculator, and another 30 seconds to calculate the value of r.

What is the slope of the least-sqaures regression line given

 $m=\frac{s_y}{s_x},\ r=0.733,\ s_x=1.871\ and\ s_y=3.391$  ?

• 0.41

• 0.45

• 1.33

• 1.87

The equation of a regression line that enables weekly amount spent on entertainment (in dollars) to be predicted from weekly income is given by:

amount = 0.10 x income + 40

What is the predicted amount spent on entertainment with a weekly income of $600?

• $40

• $46

• $100

• $240

The scatterplot shows the navel height and the body height for nine students.

What has been plotted as the independent variable?

__________________________.

Answer explanation

The independent variable is always on the x-axis.

The scatterplot shows the navel height and the body height for nine students.

What has been plotted as the dependent variable?

__________________________.

Answer explanation

The dependent variable is always on the y-axis.

The scatterplot shows the navel height and the body height for nine students.

Is the association between these two variables linear or non-linear?

The scatterplot shows the navel height and the body height for nine students.

Describe the association as strong, moderate or weak.