Final answer:
Austin's wealth has decreased by $744 after the market share price dropped from $23.30 to $21.44 over two years.
Step-by-step explanation:
When initially purchased, the value of Austin's 400 shares was at $23.30 each. After two years, the market share price dropped to $21.44. To calculate the change in Austin's wealth, we need to determine the difference in share price and then multiply by the number of shares.
The change in share price is $23.30 - $21.44 = $1.86 per share. The total decrease in wealth is 400 shares * $1.86 = $744. Therefore, Austin's wealth has decreased by $744.