Answer: The percent change was 20%.
Step-by-step explanation:
Given : Gabriel is the campaign manager for a candidate for governor.
Through a commissioned poll, he discovers that the candidate's approval rating has changed from 80 to 64 percentage.
I.e. Previous percentage = 80%
New percentage = 64%
Since 64< 80 , that means the percentage of approval has been decreased.
Decrease in percentage = (Previous percentage)- (New percentage)
= 80%-64%=16%
Percent change = ![\dfrac{\text{Decrease in percentage}}{\text{Previous percentage}}\times100](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Ctext%7BDecrease%20in%20percentage%7D%7D%7B%5Ctext%7BPrevious%20percentage%7D%7D%5Ctimes100)
![=\dfrac{16}{80}\times100\\\\=\dfrac{100}{5}\%=20\%](https://tex.z-dn.net/?f=%3D%5Cdfrac%7B16%7D%7B80%7D%5Ctimes100%5C%5C%5C%5C%3D%5Cdfrac%7B100%7D%7B5%7D%5C%25%3D20%5C%25)
Hence, the percent change was 20%.