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Finding the Fourth Proportional to 638.30, 957.54 and 221.78

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Solution

The fourth proportional to 638.30, 957.54 and 221.78 is: 332.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.30 : 957.54 = 221.78 : x
  2. Step 2: Convert to fraction form
    638.30/957.54 = 221.78/x
  3. Step 3: Cross multiply
    638.30x = 957.54 × 221.78
  4. Step 4: Simplify right side
    638.30x = 212,363.22
  5. Step 5: Solve for x
    x = 212,363.22/638.30
  6. Step 6: Final answer
    x = 332.70

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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.