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Finding the Fourth Proportional to 391.30, 538.84 and 280.58

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Solution

The fourth proportional to 391.30, 538.84 and 280.58 is: 386.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.30 : 538.84 = 280.58 : x
  2. Step 2: Convert to fraction form
    391.30/538.84 = 280.58/x
  3. Step 3: Cross multiply
    391.30x = 538.84 × 280.58
  4. Step 4: Simplify right side
    391.30x = 151,187.73
  5. Step 5: Solve for x
    x = 151,187.73/391.30
  6. Step 6: Final answer
    x = 386.37

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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.