Answer:
the percent decrease is approximately 47 %
Step-by-step explanation:
Since the quantity started at 170 and then changed to 90, there was clearly a decrease in its value.
We use the following formula to calculate the percent of decrease:
[tex]\%\,decrease = \frac{original-final}{original} \,100\\\%\,decrease = \frac{170-90}{170} \,100\\\%\,decrease = \frac{80}{170} \,100\\\%\,decrease \approx 47\,\%[/tex]
