Question

1. A chemist in interested in determining the weight loss of a particular compound as a function of the amount of time the compound is exposed to the air. The data below give the weight losses associated with settings of the exposure time.

                  Weight Loss (in pounds)           Exposure Time (in hours)

        ____________________________________________________

                          4.0                                                  4

                           6.0                                                  5

                                2.0                                             3

                           .                                                    .

                                 .                                                        .

                           9.0                                                  6

        ____________________________________________________

         Use the computer printout (below) to answer the questions.

* * * *   L I N E A R            R E G R E S S I O N   * * * *

Dependent Variable:     Weight Loss

Independent Variable: Exposure Time

                         Analysis of Variance

                              Sum of       Mean                             p

Sources     df      Squares     Squares          F          Value

-----------------------------------------------------------------------

Regression     1      70.417       70.417           F_obs         .000

Residual       10       SS_res         MS_res       

-----------------------------------------------------------------------

Total            11     84.917

---------- Variables in the Equation -----------

Variable                   B         SE B          t           p Value   

Exposure Time    2.167       0.311       6.969       0.000      

(Constant)          -5.833       1.745      -3.343       0.007

         8       points

          (a)      Why do we need to use linear regression analysis in this study?

TYPE YOUR ANSWERS BELOW:

               (1)

                  ______

               (2)

                  ______

             

         5       points

         (b)     Briefly describe the concept of least-squares regression line.

TYPE YOUR ANSWER BELOW:

                  ______

         2       points

          (c)     Why this study is called simple linear regression analysis instead

                     multiple linear regression analysis?

Answer 1