Consider a hypothesis test of difference of means for two independent populations x1 and x2. Suppose that both sample sizes are greater than 30 and that you know σ1 but not σ2. Is it standard practice to use the normal distribution or a Student's t distribution?

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

Ahiking trail is 6 miles long. it has 4 exercise stations, spaced evenly along the trail. what is the distance between each exercise station?

Ke’ajah has a coupon for 1/3 off the regular price, t, of a tent. which expression represents the price of the tent using the coupon? select the two correct expressions. a. 1/3t b. 2/3t c. t - 1/3 d. t - 2/3 e. t - 1/3t f. t - 2/3t