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Finding the Fourth Proportional to 391.79, 587.68 and 99.29

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Solution

The fourth proportional to 391.79, 587.68 and 99.29 is: 148.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.79 : 587.68 = 99.29 : x
  2. Step 2: Convert to fraction form
    391.79/587.68 = 99.29/x
  3. Step 3: Cross multiply
    391.79x = 587.68 × 99.29
  4. Step 4: Simplify right side
    391.79x = 58,350.75
  5. Step 5: Solve for x
    x = 58,350.75/391.79
  6. Step 6: Final answer
    x = 148.93

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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.