Question

9.28 Where you start matters. When comparing numbers over time, you can slant the comparison by choosing your starting point. Say the Chicago Cubs lose five games, then win four, then lose one. You can truthfully say that the Cubs have lost 6 of their last 10 games (sounds bad) or that they have won 4 of their last 5 (sounds good). The following example can also be used to make numbers sound bad or good. The median income of American households (in dollars of 2013 buying power) was $51,735 in 1990, $56,800 in 2000, and $51,939 in 2013. All three values are in dollars of 2013 buying power, which allows us to compare the numbers directly. By what percentage did household income increase between 1990 and 2013? Between 2000 and 2013? You see that you can make the income trend sound bad or good by choosing your starting point.

Answer 1

Here we can see that the values are given in dollars of 2013 buying power making the comparison easy.

Between 1990 and 2013,

Percentage difference = (51939 - 51735)*100/51735

= 0.394 %

Between 2000 and 2013,

Percentage difference = (51939 - 56800)*100/56800

= - 8.55 %

This means the income decreased by 8.55 %