A recent study examining the effects of sugar consumption on a middle school student’s ability to focus on a reading assignment used 18 volunteer subjects and divided them into 9 pairs based on their reading speeds. One randomly assigned member of each pair was given a beverage containing a substantial amount of sugar, and the other drank a sugar-free version of the beverage. Each subject was given a passage to read and the time (in seconds) it took to read was recorded. The difference for each pair is calculated (sugar – sugar-free). A 90% confidence interval for the mean difference in reading times is (-5.8, 0.15).