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Finding the Fourth Proportional to 391.25, 539.93 and 216.61

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Solution

The fourth proportional to 391.25, 539.93 and 216.61 is: 298.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.25 : 539.93 = 216.61 : x
  2. Step 2: Convert to fraction form
    391.25/539.93 = 216.61/x
  3. Step 3: Cross multiply
    391.25x = 539.93 × 216.61
  4. Step 4: Simplify right side
    391.25x = 116,950.45
  5. Step 5: Solve for x
    x = 116,950.45/391.25
  6. Step 6: Final answer
    x = 298.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.