In 1945, a microwave cost $435. Today, a microwave costs $130. What is the percent of change?

29.89%

Step-by-step explanation:

Step 1: We assume that 435 is 100% since it is our output value.  

Step 2: We next represent the value we seek with .  

Step 3: From step 1, it follows that .  

Step 4: In the same vein, .  

Step 5: This gives us a pair of simple equations:  

Step 6: By simply dividing equation 1 by equation 2 and taking note of the fact that both the LHS  (left-hand side) of both equations have the same unit (%); we have  

Step 7: Taking the inverse (or reciprocal) of both sides yields  

Therefore, is of .