During the last four years, a large truck company purchased diesel at rates of $1.2, $1.4, $1.7 and $2.1 per gallon. What was the mean cost of diesel over the four-year period if the company spends the same amount of dollars on diesel each year?
Choose the correct choice.
A) $2.5  B) $2.55  C) $1.53  D) $3.25  E) $3.0
finding the Harmonic mean here.   HM = 4/(1/12 + 1/14 + 1/17 + 1/21) = 15.31   The calculation is the same either way.   $1.53
<result>C</result>
During the last four years, a large truck company purchased diesel at rates of $1.2, $1.4, $1.7 and $2.1 per gallon. What was the mean cost of diesel over the four-year period if the company spends the same amount of dollars on diesel each year?