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Finding the Fourth Proportional to 648.20, 972 and 209.38

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Solution

The fourth proportional to 648.20, 972 and 209.38 is: 313.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.20 : 972 = 209.38 : x
  2. Step 2: Convert to fraction form
    648.20/972 = 209.38/x
  3. Step 3: Cross multiply
    648.20x = 972 × 209.38
  4. Step 4: Simplify right side
    648.20x = 203,517.36
  5. Step 5: Solve for x
    x = 203,517.36/648.20
  6. Step 6: Final answer
    x = 313.97

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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.