Question

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

Answer 1

Answer:

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 $x$.  

Step 3: From step 1, it follows that $100\%=435$.  

Step 4: In the same vein, $x\%=130$.  

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

$100\%=435(1)\\\\x\%=130(2)$  

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  

$\frac{100\%}{x\%}=\frac{435}{130}$  

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

$\frac{x\%}{100\%}=\frac{130}{435}\\\\\Rightarrow x=29.89\%$  

Therefore, $130$ is $29.89\%$ of $435$.