(1 point) Our bodies have a natural electrical field that is known to help wounds heal. Does changing the field strength slow healing? A series of experiments with newts investigated this question. The data below are the healing rates of cuts (micrometers per hour) in a matched pairs experiment. The pairs are the two hind limbs of the same newt, with the body's natural electric field in one limb (control) and half the natural electric value in the other limb (experimental). We're interested in knowing whether canceling the body's electric field reduces the healing rate. Give a 90% confidence interval for the difference in healing rates (control minus experimental).