Answer
The net percentage change in the stock market index is 0.25%
Work Step by Step
Let P be the original stock market index.
On Monday, the stock market index is 1.0500 P
On Tuesday, the stock market index is
$(0.9500)(1.0500)P = 0.9975 ~P$
We can find the percentage change in the stock market.
$\frac{(0.9975~P)-(P)}{P}\times 100\% = -0.25\%$
The net percentage change in the stock market index is 0.25%
