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Finding the Fourth Proportional to 420.78, 631.76 and 352.74

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Solution

The fourth proportional to 420.78, 631.76 and 352.74 is: 529.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.78 : 631.76 = 352.74 : x
  2. Step 2: Convert to fraction form
    420.78/631.76 = 352.74/x
  3. Step 3: Cross multiply
    420.78x = 631.76 × 352.74
  4. Step 4: Simplify right side
    420.78x = 222,847.02
  5. Step 5: Solve for x
    x = 222,847.02/420.78
  6. Step 6: Final answer
    x = 529.60

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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.