Finding the Third Proportional to 170 and 420
Calculator
Solution
The third proportional to 170 and 420 is: 1,037.65
Step by Step Solution
- Step 1: Write the proportion equation
170 : 420 = 420 : x - Step 2: Convert to fraction form
170/420 = 420/x - Step 3: Cross multiply
170x = 420 × 420 - Step 4: Simplify right side
170x = 176,400 - Step 5: Solve for x
x = 176,400/170 - Step 6: Final answer
x = 1,037.65
Related Problems
Find third proportional to 85 and 210
Half scale
Find third proportional to 340 and 840
Double scale
Find third proportional to 172 and 425
Similar ratio
Find third proportional to 255 and 630
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (2.47) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.