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Finding the Fourth Proportional to 231.68, 347.51 and 128.91

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Solution

The fourth proportional to 231.68, 347.51 and 128.91 is: 193.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.68 : 347.51 = 128.91 : x
  2. Step 2: Convert to fraction form
    231.68/347.51 = 128.91/x
  3. Step 3: Cross multiply
    231.68x = 347.51 × 128.91
  4. Step 4: Simplify right side
    231.68x = 44,796.87
  5. Step 5: Solve for x
    x = 44,796.87/231.68
  6. Step 6: Final answer
    x = 193.36

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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.