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Finding the Fourth Proportional to 391.90, 587.80 and 103.36

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Solution

The fourth proportional to 391.90, 587.80 and 103.36 is: 155.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.90 : 587.80 = 103.36 : x
  2. Step 2: Convert to fraction form
    391.90/587.80 = 103.36/x
  3. Step 3: Cross multiply
    391.90x = 587.80 × 103.36
  4. Step 4: Simplify right side
    391.90x = 60,755.01
  5. Step 5: Solve for x
    x = 60,755.01/391.90
  6. Step 6: Final answer
    x = 155.03

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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.