  ### Home > GB8I > Chapter 4 Unit 5 > Lesson INT1: 4.2.4 > Problem4-98

4-98.

Data from a study of a vitamin supplement that claims to shorten the length of the common cold is shown below:

 Number of months taking supplement Number of days cold lasted $0.5$ $2.5$ $1$ $2$ $0.5$ $1$ $2$ $1$ $1.5$ $2.5$ $4.5$ $1.6$ $3$ $1.8$ $5$ $4.2$ $2.4$ $3.6$ $3.3$ $1.4$
1. Determine the LSRL of this data again. Create a scatterplot on graph paper (or use your scatterplot from problem 4-56) and draw the LSRL.

Look at the Math Notes box in Lesson 4.2.1 to help you with LSRL graphs.

2. Is a linear model appropriate? Provide evidence.

Yes. Make sure you provide evidence for why.

3. Calculate r and interpret $R$-squared in context.

Look at the Math Notes box in Lesson 4.2.4 to refresh your memory about these values.

4. Describe the association. Make sure you describe the form and provide evidence for the form. Provide numerical values for direction and strength and interpret them in context. Describe any outliers.

• Form: Is the association linear or nonlinear?
Direction: Positive or negative?