Dr. Parton is interested in finding out whether country music affects how fast people drive. To test this hypothesis, she randomly assigns participants to either the music or the non-music condition. Participants in the non-music condition drive 10 laps around a race track without any music; participants in the music condition drive 10 laps while listening to country music. What type of test statistic should she use to answer her research question?

• One-sample z-test
• t-test for the significance of the correlation coefficient
• t-test for dependent samples
• t-test for independent samples
• simple analysis of variance