Chapter 11.2, Problem 30E

The paper referenced in the previous exercise also had the 50 taxi drivers drive in the simulator while sending and receiving text messages. The mean of the 50 sample differences (no distraction – reading text messages) was 1.3 meters and the standard deviation of the sample differences was 1.54 meters. The authors concluded that there was evidence to support the claim that the mean following distance for Greek taxi drivers is greater when there are no distractions than when the driver is texting. Do you agree with this conclusion? Carry out a hypothesis test to support your answer. You can assume that this sample of 50 drivers is representative of Greek taxi drivers.

11.29 The paper “Driving Performance While Using a Mobile Phone: A Simulation Study of Greek Professional Drivers” (Transportation Research Part F [2016]: 164–170) describes a study in which 50 Greek male taxi drivers drove in a driving simulator. In the simulator, they were asked to drive following a lead car. On one drive, they had no distractions and the average distance between the driver’s car and the lead car was recorded. In a second drive, the drivers talked on a mobile phone while driving. The authors of the paper used a paired-sampled t test to determine if the mean following distance is greater when the driver has no distractions than when the driver is talking on a mobile phone. The mean of the 50 sample differences (no distraction – talking on mobile phone) was 0.47 meters and the standard deviation of the sample differences was 1.22 meters. The authors concluded that there was evidence to support the claim that the mean following distance for Greek taxi drivers is greater when there are no distractions than when the driver is talking on a mobile phone. Do you agree with this conclusion? Carry out a hypothesis test to support your answer. You may assume that this sample of 50 drivers is representative of Greek taxi drivers.