Tuesday:
30.80 + 1.20 = 32.00
Falling by 6.25% means it ends up being 93.75% of what it used to be (100% - 6.25% = 93.75%)
Wednesday:
32.00 * 0.9375 = 30
Thursday:
30 * 0.96 = 28.8
Friday:
28.8 * 1.025 = 29.52
Net change means you subtract to get the difference.
Net change = Final - initial
= 29.52 - 30.80
= -1.28
The stock fell $1.28
Hope this helps!