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Finding the Fourth Proportional to 648.30, 972.45 and 209.55

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Solution

The fourth proportional to 648.30, 972.45 and 209.55 is: 314.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.30 : 972.45 = 209.55 : x
  2. Step 2: Convert to fraction form
    648.30/972.45 = 209.55/x
  3. Step 3: Cross multiply
    648.30x = 972.45 × 209.55
  4. Step 4: Simplify right side
    648.30x = 203,776.90
  5. Step 5: Solve for x
    x = 203,776.90/648.30
  6. Step 6: Final answer
    x = 314.33

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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.