Finding the Third Proportional to 220 and 420
Calculator
Solution
The third proportional to 220 and 420 is: 801.82
Step by Step Solution
- Step 1: Write the proportion equation
220 : 420 = 420 : x - Step 2: Convert to fraction form
220/420 = 420/x - Step 3: Cross multiply
220x = 420 × 420 - Step 4: Simplify right side
220x = 176,400 - Step 5: Solve for x
x = 176,400/220 - Step 6: Final answer
x = 801.82
Related Problems
Find third proportional to 110 and 210
Half scale
Find third proportional to 440 and 840
Double scale
Find third proportional to 222 and 424
Similar ratio
Find third proportional to 330 and 630
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.91) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.