Finding the Third Proportional to 391 and 415
Calculator
Solution
The third proportional to 391 and 415 is: 440.47
Step by Step Solution
- Step 1: Write the proportion equation
391 : 415 = 415 : x - Step 2: Convert to fraction form
391/415 = 415/x - Step 3: Cross multiply
391x = 415 × 415 - Step 4: Simplify right side
391x = 172,225 - Step 5: Solve for x
x = 172,225/391 - Step 6: Final answer
x = 440.47
Related Problems
Find third proportional to 195.50 and 207.50
Half scale
Find third proportional to 782 and 830
Double scale
Find third proportional to 393 and 417
Similar ratio
Find third proportional to 586.50 and 622.50
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.06) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.