Forty volunteer drivers are separated into two groups of 20 drivers each at random. The first group is asked to pay particular attention to braking smoothly when approaching a red light or stop sign. The second group is given no special instructions. All drivers report, at the end of a month, the gallons of gasoline used.
A.The difference in means for the two treatment groups is likely due to the random assignment since the difference is negative.
B.The difference in means for the two treatment groups is likely due to the random assignment since there is at least one value in the histogram with a greater absolute difference than 11.47 gallons of gas.
C.The randomization distribution does not give any evidence that the difference between the two treatment groups is due to the special
Instructions.
D.The randomization distribution provides strong evidence that the difference in means for the two treatment groups is due to the treatment because the difference is highly unlikely based on random assignment alone.
