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Finding the Fourth Proportional to 648.60, 972.90 and 215.75

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Solution

The fourth proportional to 648.60, 972.90 and 215.75 is: 323.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.60 : 972.90 = 215.75 : x
  2. Step 2: Convert to fraction form
    648.60/972.90 = 215.75/x
  3. Step 3: Cross multiply
    648.60x = 972.90 × 215.75
  4. Step 4: Simplify right side
    648.60x = 209,898.31
  5. Step 5: Solve for x
    x = 209,898.31/648.60
  6. Step 6: Final answer
    x = 323.62

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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.