In: Statistics and Probability
Because of the rising costs of industrial accidents, many chemical, mining, and manufacturing firms have instituted safety courses. Employees are encouraged to take these courses designed to heighten safety awareness among them. A company is trying to decide which one of two courses to institute. To help make a decision, eight employees take course 1, and another group of eight take course 2. Each employee takes a test, which is graded out of a possible 25 marks. The safety test results of these employees are shown below. Assume that the scores are normally distributed.
Course 1 Course 2
Sample Mean 12.3750 19.1250
Sample SD 2.7222 2.9970
SD=Standard Deviation
Do these data provide enough evidence at the 5% level of
significance to infer that the marks from course 1 are lower than
those of course 2?