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Finding the Fourth Proportional to 391.60, 539.92 and 258.60

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Solution

The fourth proportional to 391.60, 539.92 and 258.60 is: 356.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.60 : 539.92 = 258.60 : x
  2. Step 2: Convert to fraction form
    391.60/539.92 = 258.60/x
  3. Step 3: Cross multiply
    391.60x = 539.92 × 258.60
  4. Step 4: Simplify right side
    391.60x = 139,623.31
  5. Step 5: Solve for x
    x = 139,623.31/391.60
  6. Step 6: Final answer
    x = 356.55

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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.