Do polyurethane swimsuits help swimmers swim faster, on average? To investigate, Lauren, a statistics student and competitive swimmer had 8 volunteers from her swim team participate in an experiment. On two consecutive Saturdays, she had each swimmer perform the same warm-up routine and swim a 50-meter freestyle. On one Saturday, the swimmer wore a polyurethane suit and on the other Saturday, the swimmer wore a traditional suit, with the order determined at random for each swimmer. The results for each swimmer are shown in the table. Note that the smaller times are better!

Is there convincing evidence that polyurethane swimsuits help swimmers like these swim faster than traditional suits, on average.

Swimmer Adah Caitlyn Griff Leighann Kwame Amara Matt Kirsten Traditional Suit 26.32 28.13 27.06 27.97 25.24 28.32 26.77 27.66 Polyurethane Suit 25.89 28.01 27.33 27.22 24.44 28.29 26.91 27.01