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Finding the Fourth Proportional to 487.86, 728.76 and 439.02

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Solution

The fourth proportional to 487.86, 728.76 and 439.02 is: 655.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.86 : 728.76 = 439.02 : x
  2. Step 2: Convert to fraction form
    487.86/728.76 = 439.02/x
  3. Step 3: Cross multiply
    487.86x = 728.76 × 439.02
  4. Step 4: Simplify right side
    487.86x = 319,938.16
  5. Step 5: Solve for x
    x = 319,938.16/487.86
  6. Step 6: Final answer
    x = 655.80

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.