#### Question

# Algebra absolute value help (Quick 10pts)?

A thermometer measures 5 body temperatures accurately to within +/- 0.15 degrees F. Which of the following is an expression for the actual temperature t of a person if this thermometer measures the person's temperature as 98.5 degrees F?

l t - 98.5 l </= 0.15 (</= is my attempt at less than or equal to and "l" is the absolute value)

l t + 98.5 l </=0.15

l t - 98.5 l >/=0.15

l t + 98.5 l >/=0.15

PLEASE ANSWER! I will award 10 points to answer with the most detail.

#### Answers

The thermometer is actually telling you that the temperature is somewhere between 98.5 + .15 and 98.5 - .15

That is the same as saying 98.5 - .15 < t < 98.5 + .15

Which is the same as -.15 < t - 98.5 < .15

Which means l t - 98.5 l </= 0.15

The first, because if both are equal,(no error) it will be I t-98.5 I = 0.0 and if t gets bigger or smaller in +/- 0.15 t will always be more than 0 and less than 0.15