In: Math
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.
Day | Rounds | ||
Monday | 130 | ||
Tuesday | 120 | ||
Wednesday | 110 | ||
Thursday | 140 | ||
Friday | 125 | ||
At the 0.05 significance level, is there a difference in the number of rounds played by day of the week?
H0: Rounds played is the same for each
day.
H1: Rounds played is not the same.
State the decision rule, using the 0.05 significance level.
Compute the value of chi-square.
What is your decision regarding H0?
Answer:
The given data is,
Day | Rounds (fo) |
Monday | 130 |
Tuesday | 120 |
Wednesday | 110 |
Thursday | 140 |
Friday | 125 |
Step 1: Set the null and alternate hypotheses
The null and alternate hypotheses can be stated as:
H0: Rounds played is the same for each day.
H1: Rounds played is not the same.
Step 2: Determine the appropriate statistical test
The appropriate test statistic is
where, fo = observed frequencies and fe = expected frequencies.
with df = k - 1 - c
Step 3: Set the level of significance
Alpha has been specified as 0.05.
Step 4: Set the decision rule
For a given level of significance 0.05, rules for acceptance or rejection of null hypothesis are as below:
If
, reject the null hypothesis, otherwise, do not reject the null
hypothesis.
The critical
value is
where degrees of freedom = n - 1 = 5 - 1 = 4.
Step 5: Analyse the data
Expected frequencies can be computed by dividing total observed
frequencies by number of days. In this case, expected frequency =
Day | fo | fe | ![]() |
Monday | 130 | 125 | 0.2 |
Tuesday | 120 | 125 | 0.2 |
Wednesday | 110 | 125 | 1.8 |
Thursday | 140 | 125 | 1.8 |
Friday | 125 | 125 | 0 |
Total | ![]() |
4 |
So,
Step 6: Arrive at a statistical conclusion:
At 95% confidence level, the critical value obtained from the
table is
. Calculated
value 4, which is less than the tabular value and falls in the
acceptance region. Hence, the null hypothesis is accepted and the
alternative hypothesis is rejected. Therefore, we conclude that
rounds played is the same for each day.