Steps
So here are a couple expressions when a value changes by percentage (p = percentage in decimal form and m = original value):
- When decrease: (1 - p)m
- When increase: (1 + p)m
So firstly, the $80 share dropped by 15%. Since this is a decrease, follow the appropriate expression:
[tex]15\%=0.15\\\\(1-0.15)*80\\0.85*80\\68[/tex]
On Tuesday, the share went from $80 to $68
Next, on Wednesday the share increased by $7. With this, just add $68 and 7.
[tex]68+7=75[/tex]
On Wednesday, the share went from $68 to $75
Lastly, on Thursday the share increased by 12%. Since this is an increase, follow the appropriate expression:
[tex]12\%=0.12\\\\(1+0.12)*75\\1.12*75\\84[/tex]
Answer
The final price of the share is $84.
