Real-Life Math -- Solution
By calculating the increase in the potassium rate in the eye over
a 2-hour period, you should be able to work back to the time when the person
died.
These are your measurements:
Measurement
1 Time = 2 p.m.
Potassium level = 10
Measurement 2 Time
= 4 p.m.
Potassium level = 12
In 2 hours, the
potassium level in the eye has increased by 2 microliters. You can use this
to determine how much time has passed since the potassium level in the eye
was 6 microliters -- the normal level.
For each 2-hour increment, the
level goes up by 2 microliters. If the level goes up by 2 each 2 hours, then
it would take 2 increments -- or 4 hours -- to reach the 1st reading of 10
at 2 p.m. (10 - 6 = 4)
So, if the person died 4 hours before 2 p.m.,
then the estimated time of death would be 10 a.m.
Real-life forensic
pathologist Paul Hoyer says he uses math skills every day in his job. "I have
to measure injuries, toxicology levels and I have to calculate back to find
out the time of death," he says.