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Finding the Fourth Proportional to 487.50, 672.43 and 421.38

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Solution

The fourth proportional to 487.50, 672.43 and 421.38 is: 581.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.50 : 672.43 = 421.38 : x
  2. Step 2: Convert to fraction form
    487.50/672.43 = 421.38/x
  3. Step 3: Cross multiply
    487.50x = 672.43 × 421.38
  4. Step 4: Simplify right side
    487.50x = 283,348.55
  5. Step 5: Solve for x
    x = 283,348.55/487.50
  6. Step 6: Final answer
    x = 581.23

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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.