A quality control manager for a city transportation department wants to improve customer satisfaction. To assess the current customer satisfaction level, the manager counts the number of customer complaints for 30 days.

The manager performs a 1-sample Poisson rate test to determine whether the average rate of complaints per day is greater than 10.

- Open the sample data, CustomerComplaints.MTW.
- Choose .
- From the drop-down list, select One or more samples, each in a column.
- In Sample columns, enter Number of complaints.
- Select Perform hypothesis test.
- In Hypothesized rate, enter
`10`. - Select Options.
- From Alternative hypothesis, select Rate > hypothesized rate.
- Click OK in each dialog box.

The null hypothesis states that the rate is 10 complaints per day. Because the p-value of 0.000 is less than the significance level of 0.05 (denoted by α or alpha), the manager rejects the null hypothesis and concludes that the rate of complaints is greater than 10 per day.

Method
λ: Poisson rate of Number of complaints
Exact method is used for this analysis.

Descriptive Statistics
Total 95% Lower
N Occurrences Sample Rate Bound for λ
30 598 19.9333 18.6118

Test
Null hypothesis H₀: λ = 10
Alternative hypothesis H₁: λ > 10