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Finding the Fourth Proportional to 648.77, 972.20 and 319.61

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Solution

The fourth proportional to 648.77, 972.20 and 319.61 is: 478.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.77 : 972.20 = 319.61 : x
  2. Step 2: Convert to fraction form
    648.77/972.20 = 319.61/x
  3. Step 3: Cross multiply
    648.77x = 972.20 × 319.61
  4. Step 4: Simplify right side
    648.77x = 310,718.38
  5. Step 5: Solve for x
    x = 310,718.38/648.77
  6. Step 6: Final answer
    x = 478.94

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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.