Data Chart

Question

  Eye Color
Hair Color :   Blue Gray Green Brown Marginal Total
Blond             42     5        21       10         78

Red                12     22      19       12         65
Brown            22      5        12       34        73
Black              9       3        11       64        87
Marginal Total:85    35      63       120      303

As part of a class project, a university student surveyed students in the cafeteria to look for a relationship between the students’ eye color and hair color. The table contains the survey results.

The percentage of the sample population with brown eyes and black hair is larger than the percentage of the sample population with blue eyes and black hair by _______________percentage points. (Round off your answer to the nearest whole number.)

Answer 1

1.  Read the table:

    The number of observations with brown eyes and black hair is 64.

    The number of observations with blue eyes and black hair is 9.

    The sample population is 303.

 

2.  Calculate percentages:

       64/303 = 0.211221  or 21.1%

       9/303 = 0.029703    or  3.0 %

 

3.  Calculate the difference

      21.1% - 3.0% = 18.1%

       18% rounded to the nearest whole number