Answer:
19.04%
Step-by-step explanation:
The temperature decreases from 21°C to 17°C.
We need to find the percentage decrease in the value of temperatures.
The percentage decrease in any value is given by :
[tex]\%=\dfrac{|\text{initial value-final value}|}{\text{initial value}}\times 100\\\\=\dfrac{21-17}{21}\times 100\\\\=19.04\%[/tex]
So, the required percentage decrease is 19.04%.
