The gear-cutting department in a large manufacturing firm produces high-quality gears. The number produced per hour by a single machinist is 1, 2, or 3, as shown in the table. Company management is interested in determining the effect of worker experience on the number of units produced per hour. Worker experience is classified in three subgroups: 1 year or less, 2 to 5 years, and more than 5 years. Use the data in the table to determine if experience and number of parts produced per hour are independent.

Units Produced/Hour Experience 1 2 3 Total

…1 year 10 30 10 50 2–5 years 10 20 20 50 75 years 10 10 30 50 Total 30 60 60 150