Charting, page-899

Which is correct but only because you bought equal share parcels.

A more generalized calculation method is as follows...
Total Amount of Money invested = (1,000 X 0.53) + (1,000 X 0.93) = $1,460
Divided by total number of shares finally owned = 2,000
$1,460 / 2,000 = 0.73 per share

This generalized method allows for dissimilar sized share parcels to be averaged,

For example, what if you bought...

2,000 shares at 0.53
5,000 shares at 0.68
1,000 shares at 0.93 ?

Total Money Invested = 2,000 X 0.53 + 5,000 X 0.68 + 1,000 X 0.93 = 1,060 + 3,400 + 930 = $5,390
Divided by total shares owned = 2,000 + 5,000 + 1,000 = 8,000
$5,390 / 8,000 = $0.674 per share (average)