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Finding the Fourth Proportional to 391.12, 586.79 and 131.15

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Solution

The fourth proportional to 391.12, 586.79 and 131.15 is: 196.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.12 : 586.79 = 131.15 : x
  2. Step 2: Convert to fraction form
    391.12/586.79 = 131.15/x
  3. Step 3: Cross multiply
    391.12x = 586.79 × 131.15
  4. Step 4: Simplify right side
    391.12x = 76,957.51
  5. Step 5: Solve for x
    x = 76,957.51/391.12
  6. Step 6: Final answer
    x = 196.76

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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.