Question

1. Say that you spend an average of 10 hours on Reddit a week, and you’re wondering if you might be slightly addicted. You will decide you may need to take corrective action only if this is significantly more than the average number of hours the population of Redditors spend browsing Reddit.

a. Define the parameter of interest

b. State the relevant hypotheses.

2. There’s a restaurant you really like but recently, when you’ve gone, it seems like you have had to wait in lines more frequently. You’re wondering if the true proportion of times you have to wait has increased.

a. Define the parameter of interest

b. State the relevant hypotheses.

3. Say bus number 57 is supposed to arrive once every 15 minutes. You wonder if it’s really on schedule, so you pick a random sample and record how much time passes between bus arrivals to your stop.

a. Define the parameter of interest

b. State the relevant hypotheses. 1

4. Lyft is always offering promotions like “$5 off next 10 lyft rides”. Their business team proposes a new kind of promotion and does a test-release to see if the proportion of users who book rides during the promotion period increases.

a. Define the parameter of interest

b. State the relevant hypotheses.

Answer 1

1. a) Here the parameter of interest is u, the average number if hours spent by the population of Reddit users browsing it in a week.

b) H0: u= 10 vs H1: u>10

2. a) parameter of interest is p= proportion of times of waiting in line

b) H0: p is still the same H1: p has increased

3. a) parameter of interest is the time between bus arrivals to my stop.

H0: u= 15 vs H1: u>15

4. a. Parameter of interest p= proportion of users who book rides

b. H0: p stays the same during promotion period

H1: p increases during promotion period.