Question: An experiment was conducted to compare the effectiveness of three training programs, A, B, and C, in training assemblers of a piece of electronic equipment. Fifteen employees were randomly assigned, 5 each, to the three programs. After the completion of the courses, each person was required to assemble four pieces of equipment, and the average length of time required to complete the assembly was recorded. Owing to resignation from the company, only 4 employees completed the program A and only 3 completed the program B while all 5 employees completed the program C. The result is as follows:

Do the data provides sufficient evidence to indicate a difference in mean assembly times for people trained by the three programs at a 95% confidence level?