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Finding the Fourth Proportional to 487.11, 671.85 and 421.50

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Solution

The fourth proportional to 487.11, 671.85 and 421.50 is: 581.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.11 : 671.85 = 421.50 : x
  2. Step 2: Convert to fraction form
    487.11/671.85 = 421.50/x
  3. Step 3: Cross multiply
    487.11x = 671.85 × 421.50
  4. Step 4: Simplify right side
    487.11x = 283,184.78
  5. Step 5: Solve for x
    x = 283,184.78/487.11
  6. Step 6: Final answer
    x = 581.36

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.