Question

You are conducting research for the US Dept. of Transportation (USDOT). USDOT wants to know if people drive at different speeds (in miles per hour, mph's) when they are by themselves than when they have passengers in the car. Given only this inform­ation, you should use a ______test with the region of rejection in ______.

1. 		non-directional; both tails
   		non-directional; upper tail
   		directional; the lower tail
   		directional; the upper tail

USDOT are interested in knowing effect of some factors on driving speed (mph). You are given data (driving speed) of drivers classified by the "presence of passengers" (none vs. some) and by "gender of the driver" (male vs. female). You should analyze these data using a:

1. 		Two-way chi-square test of association.
   		t for two independent samples.
   		t for two matched (or dependent) samples.
   		Two-way Analysis of Variance.

Answer 1

P1: Since USDOT wants to know if people drive at different speeds (in miles per hour, mph's) when they are by themselves than when they have passengers in the car,

you should use a non-directional test with the region of rejection in both tails.

P2: Since USDOT are interested in knowing effect of some factors on driving speed (mph) , there are two factors:  "presence of passengers" and "gender of the driver" and each have two levels. Hence we use:

Option: Two-way Analysis of Variance.