Ellen Wants to See If the Level of Lighting in a Room

Multiple Choice

Ellen wants to see if the level of lighting in a room will affect the performance of individuals on an IQ test.One group in her study is placed in a room with very bright lights and a second group is placed in a room with more normal lighting.She finds that the individuals in the bright light group have better scores on the test than do the individuals in the normal light group.The difference between the two groups' scores is statistically significant,which means that the ____.

A) lighting definitely makes a difference
B) difference between the groups is due to chance
C) lighting significantly affects performance
D) difference between the groups is probably not due to chance