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Two Means - Known Variance
10. Hypothesis Testing for Two Samples / Two Means - Known Variance / Problem 1
Problem 1

A nutritionist randomly assigned 6565 students to receive either a regular (150 mL150\(\text{ mL}\)) or extra-large (300 mL300\(\text{ mL}\)) smoothie before class. After class, the nutritionist measured how much smoothie each student drank. The 3232 students with the regular smoothie drank an average of 92.4 mL92.4\(\text{ mL}\) with a standard deviation of 18.2 mL18.2\(\text{ mL}\). The 3333 students with the extra-large smoothie drank an average of 121.7 mL121.7\(\text{ mL}\) with a standard deviation of 15.5 mL15.5\(\text{ mL}\). Construct a 95%95\% confidence interval for the difference in mean smoothie consumption between the two groups.