A psychology professor is interested in whether there is a relationship between reaction time and age. The following data are collected on thirty individuals randomly sampled from the city in which the professor works. Random sampling is conducted in a manner to ensure that a wide age range is represented in the sample.

 

a. Use SPSS to construct a scatter plot of the data. Name the variables RT and Age. Assign RT as the Y axis variable and Age as the X axis variable.

  

b. Describe the relationship.

  

c. Use SPSS to compute Pearson r.

  

d. How much of the variability of RT is accounted for by Age?   

Subject No. 1 2 3 4 5 6. 7 8 10 RT (msec) 300 538 832 747 610 318 822 693 461 460 Age (yrs) 24.6 28.5 45.2 31.1 22.0 14.4 57.9 55.0 37.3 14.0 Subject No. 11 12 13 14 15 16 17 18 19 20 RT (msec) 418 706 830 584 515 222 740 582 398 661 Age (yrs) 24.7 41.5 51.3 45.8 19.0 10.0 57.4 32.2 19.7 25.7 Subject No. 21 22 23 24 25 26 27 28 29 30 RT (msec) 605 890 717 610 803 702 241 360 890 424 Age (yrs) 52.1 55.4 46.0 38.6 39.7 34.4 15.0 29.2 59.5 32.0