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Finding the Fourth Proportional to 231.72, 347.47 and 85.43

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Solution

The fourth proportional to 231.72, 347.47 and 85.43 is: 128.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.72 : 347.47 = 85.43 : x
  2. Step 2: Convert to fraction form
    231.72/347.47 = 85.43/x
  3. Step 3: Cross multiply
    231.72x = 347.47 × 85.43
  4. Step 4: Simplify right side
    231.72x = 29,685.26
  5. Step 5: Solve for x
    x = 29,685.26/231.72
  6. Step 6: Final answer
    x = 128.11

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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.