The line graph illustrates the number of hours required to produce a refrigerator in three companies—A, B, and C—over a 10-year period from 1990 to 2000. Overall, both company A and company C experienced a gradual decline in production time over the decade, while company B relatively remained stable throughout.
In 1990, company A recorded the highest production time, at around 35 hours per unit. Although this figure declined steadily to below 30 hours by the end of the period, it maintained the top position among the three companies. A similar downward trend was observed in company C, which began at approximately 30 hours in 1990 for refrigerator production; then production time dropped consistently to a low of 22 hours per unit, making it the most time-efficient producer by 2000.
In contrast, company B recorded minimal variation, with its production time fluctuating only slightly between 26 and 27 hours, indicating a relatively consistent manufacturing process throughout the entire period.
