Home / 428,403.90-642,740.16-257,811.78

Finding the Fourth Proportional to 428,403.90, 642,740.16 and 257,811.78

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Solution

The fourth proportional to 428,403.90, 642,740.16 and 257,811.78 is: 386,798.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    428,403.90 : 642,740.16 = 257,811.78 : x
  2. Step 2: Convert to fraction form
    428,403.90/642,740.16 = 257,811.78/x
  3. Step 3: Cross multiply
    428,403.90x = 642,740.16 × 257,811.78
  4. Step 4: Simplify right side
    428,403.90x = 165,705,984,727.09
  5. Step 5: Solve for x
    x = 165,705,984,727.09/428,403.90
  6. Step 6: Final answer
    x = 386,798.50

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.