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Finding the Fourth Proportional to 648.64, 972.96 and 215.70

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Solution

The fourth proportional to 648.64, 972.96 and 215.70 is: 323.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.64 : 972.96 = 215.70 : x
  2. Step 2: Convert to fraction form
    648.64/972.96 = 215.70/x
  3. Step 3: Cross multiply
    648.64x = 972.96 × 215.70
  4. Step 4: Simplify right side
    648.64x = 209,867.47
  5. Step 5: Solve for x
    x = 209,867.47/648.64
  6. Step 6: Final answer
    x = 323.55

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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.