Finding the Third Proportional to 420 and 618
Calculator
Solution
The third proportional to 420 and 618 is: 909.34
Step by Step Solution
- Step 1: Write the proportion equation
420 : 618 = 618 : x - Step 2: Convert to fraction form
420/618 = 618/x - Step 3: Cross multiply
420x = 618 × 618 - Step 4: Simplify right side
420x = 381,924 - Step 5: Solve for x
x = 381,924/420 - Step 6: Final answer
x = 909.34
Related Problems
Find third proportional to 210 and 309
Half scale
Find third proportional to 840 and 1,236
Double scale
Find third proportional to 422 and 621
Similar ratio
Find third proportional to 630 and 927
1.5x scale
Why These Related Problems?
These problems maintain the same ratio (1.47) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.