Classic Golf Inc manages five courses in the Jacksonville Fl

  Classic Golf Inc. manages five courses in the Jacksonville, Florida, area. The director of golf wishes to study the number of rounds of golf played per weekday at the five courses. He gathered the following sample information shown to the left. At the .05 significance level, is there a difference in the number of rounds played by day of the week?

Day

Round

Monday

124

Tuesday

74

Wednesday

104

Thursday

98

Friday

120

Solution

The total for all days is 124 + 74 + 104 + 98 + 120 = 520. If there was no difference, then the expected frequency for each day would be 520/5 = 104.

Then compute the chi square test statistic by taking each observed value, subtracting the expected, squaring that and then dividing by the expected value.

For example, for the Monday, (124-104)^2/104 = 3.846153846. Then you add them up.

observed

expected

(observed - expected)^2/expected

124

104

3.846153846

74

104

8.653846154

104

104

0

98

104

0.346153846

120

104

2.461538462

total:

15.30769231

The total is the chi square test statistic, which is 15.308.

Looking up on the chi square table under .05 at 5-1 = 4 degrees of freedom, the critical value is 9.488.

Since our test statistic is greater than the critical value, at a .05 significance level there is a difference in the number of rounds played by day of the week.