Question 3 Vertex Corporation has two supermarket stores in a city. The company's quality control department wanted to check if the customers are equally satisfied with the services provided at these two stores. A sample of 275 customers selected from Supermarket I produce a mean satisfaction index of 7.6 (on a scale of 1 to 10, 1 being the lowest and 10 being the highest) with a standard deviation of 0.75. Another sample of 300 customers selected from Supermarket II produced a mean satisfaction index of 8.0 with a standard deviation of 0.72. Test at 1% level of significance whether the mean satisfaction indexes for all customers for the two supermarkets are different. (8 marks)