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Finding the Fourth Proportional to 648.20, 972.21 and 339.95

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Solution

The fourth proportional to 648.20, 972.21 and 339.95 is: 509.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.20 : 972.21 = 339.95 : x
  2. Step 2: Convert to fraction form
    648.20/972.21 = 339.95/x
  3. Step 3: Cross multiply
    648.20x = 972.21 × 339.95
  4. Step 4: Simplify right side
    648.20x = 330,502.79
  5. Step 5: Solve for x
    x = 330,502.79/648.20
  6. Step 6: Final answer
    x = 509.88

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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.