Annual income

The annual income (in thousands of $) of fifteen families is 60, 80, 90, 96, 120, 150, 200, 360, 480, 520, 1060, 1200, 1450, 2500, 7200. Calculate the harmonic and geometric mean.

Correct answer:

h =  186.37
g =  377.21

Step-by-step explanation:

$$\begin{gathered} s_0=1/60+1/80+1/90+1/96+1/120+1/150+1/200+1/360+1/480+1/520+1/1060+1/1200+1/1450+1/2500+1/7200\doteq 0.0805 \\ h=15/s_0=15/0.0805=186.37 \end{gathered}$$

$$\begin{gathered} s_1=60\cdot 80\cdot 90\cdot 96\cdot 120\cdot 150\cdot 200\cdot 360\cdot 480\cdot 520\cdot 1060\cdot 1200\cdot 1450\cdot 2500\cdot 7200=4.4538150764151\cdot 10^{38} \\ g=s_1^{1/15}=\sqrt[15]{4.4538150764151\cdot 10^{38}}=377.21 \end{gathered}$$

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