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Finding the Fourth Proportional to 312.87, 469.24 and 221.28

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Solution

The fourth proportional to 312.87, 469.24 and 221.28 is: 331.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.87 : 469.24 = 221.28 : x
  2. Step 2: Convert to fraction form
    312.87/469.24 = 221.28/x
  3. Step 3: Cross multiply
    312.87x = 469.24 × 221.28
  4. Step 4: Simplify right side
    312.87x = 103,833.43
  5. Step 5: Solve for x
    x = 103,833.43/312.87
  6. Step 6: Final answer
    x = 331.87

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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.