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Finding the Fourth Proportional to 517.60, 775.40 and 421.12

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Solution

The fourth proportional to 517.60, 775.40 and 421.12 is: 630.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    517.60 : 775.40 = 421.12 : x
  2. Step 2: Convert to fraction form
    517.60/775.40 = 421.12/x
  3. Step 3: Cross multiply
    517.60x = 775.40 × 421.12
  4. Step 4: Simplify right side
    517.60x = 326,536.45
  5. Step 5: Solve for x
    x = 326,536.45/517.60
  6. Step 6: Final answer
    x = 630.87

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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.