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Finding the Fourth Proportional to 391.46, 540.42 and 286.79

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Solution

The fourth proportional to 391.46, 540.42 and 286.79 is: 395.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.46 : 540.42 = 286.79 : x
  2. Step 2: Convert to fraction form
    391.46/540.42 = 286.79/x
  3. Step 3: Cross multiply
    391.46x = 540.42 × 286.79
  4. Step 4: Simplify right side
    391.46x = 154,987.05
  5. Step 5: Solve for x
    x = 154,987.05/391.46
  6. Step 6: Final answer
    x = 395.92

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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.