Browsing as Guest. Progress, bookmarks and attempts are disabled.
Log in to track your work.
Nov 2012 p61 q2
2526
The amounts of money, x dollars, that 24 people had in their pockets are summarised by \(\Sigma(x - 36) = -60\) and \(\Sigma(x - 36)^2 = 227.76\). Find \(\Sigma x\) and \(\Sigma x^2\).
Solution
We start with the equation \(\Sigma(x - 36) = -60\). Expanding this gives:
\(\Sigma x - 24 \times 36 = -60\)
\(\Sigma x = 24 \times 36 - 60 = 804\)
Next, we use \(\Sigma(x - 36)^2 = 227.76\). Expanding gives: