Question

"Glycemic index” is a measure of how quickly blood sugar level rises after eating a particular food. (Glucose has a glycemic index of 100, while water has a glycemic index of 0.) A group of researchers wished to study glycemic index when dates and coffee were consumed together by individuals with type 2 diabetes. They performed a study on 10 subjects with diabetes. Firstly, they measured glycemic index for each patient after consuming dates without coffee. The mean was 53 with standard deviation 19. Then (several days later) they measured glycemic index for each patient after consuming dates with coffee. The mean was 41.5 with standard deviation 17. The differences between the measurements (“without coffee” minus “with coffee”) had mean 11.5 with standard deviation 21.

1. Find a 95% confidence interval for the population mean difference between the date glycemic index measurements (“without coffee” minus “with coffee.”)

2.The P-value you found was greater than 0.05, so the authors did not reject the null hypothesis. Based on this and the rest of analysis, is it correct to conclude that we are sure that on average, dates have the same glycemic index with or without coffee? Explain.

Answer 1