Exercise

Getting to Work With Confidence: Choosing a Departure Time

Donny doesn't like to wake up early, so he often arrives late to work. Donny blames his lateness on traffic. While Donny usually leaves home 10 minutes before work and his commute takes 10 minutes on average, his commute often takes longer than that. For a year, Donny, measures exactly how many minutes his morning commute takes, and records it in the vector Commute. Let's use this information to help Donny figure out when he should leave for work if he wants to arrive to work on time.

Instructions

100 XP
  • 1) Assuming that Donny's sample is representative of the true distribution of commute times, use the vector Commute to determine how much time Donny should leave for his commute if he wants to arrive to work on time at least 95% of the time.
  • 2) Since Donny's sample is subject to error, determine how much time Donny should leave for his commute if he wants to arrive to work on time approximately 50% of the time with 95% confidence.