A city planner randomly selects 50 adults who live in the city, 50 adults who live in a rural community, and 50 adults who live in the suburbs. Each person is asked about how long they drive to work. The results are displayed in the tables.

Observed counts:



Expected counts:



The city planner would like to know if there is a difference in the distribution of commute distance for the populations of all people who live in the city, in a rural community, and in the suburbs, so she decides to test these hypotheses:

H0: There is no difference in the distribution of commute distance for the populations of all people who live in the city, in a rural community, and in the suburbs.
Ha: There is a difference in the distribution of commute distance for the populations of all people who live in the city, in a rural community, and in the suburbs.

The conditions for inference are met. What is the value of the chi-square test statistic and what are the degrees of freedom for this test?

χ‑2 = 7.47, df = 4
χ‑2 = 7.47, df = 8
χ‑2 = 55.86, df = 4
χ‑2 = 55.86, df = 8