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Finding the Fourth Proportional to 231.90, 347.85 and 87.72

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Solution

The fourth proportional to 231.90, 347.85 and 87.72 is: 131.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.90 : 347.85 = 87.72 : x
  2. Step 2: Convert to fraction form
    231.90/347.85 = 87.72/x
  3. Step 3: Cross multiply
    231.90x = 347.85 × 87.72
  4. Step 4: Simplify right side
    231.90x = 30,513.40
  5. Step 5: Solve for x
    x = 30,513.40/231.90
  6. Step 6: Final answer
    x = 131.58

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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.