Variations in the resistivity of blood can give valuable clues to changes in the blood's viscosity and other properties. the resistivity is measured by applying a small potential difference and measuring the current. suppose a medical device attaches electrodes into a 1.5-mm-diameter vein at two points 5.0 {\rm cm} apart. what is the blood resistivity if a 8.9 v potential difference causes a 240 \mu a current through the blood in the vein (in omega*m)?