A researcher was studying the effects of time-of-day decision-making in critical-care settings. The independent variable was time of day, and the dependent variable was a confidence score based on a survey instrument. The scores and times of day are shown in the table below.

Early morning	Early afternoon	Evening
12 14 17 18 19 15 16 17 15	16 18 19 21 18 17 15 19 22	20 22 22 19 19 18 17 15 19