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Finding the Fourth Proportional to 81.40, 112.36 and 51.88

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Solution

The fourth proportional to 81.40, 112.36 and 51.88 is: 71.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.40 : 112.36 = 51.88 : x
  2. Step 2: Convert to fraction form
    81.40/112.36 = 51.88/x
  3. Step 3: Cross multiply
    81.40x = 112.36 × 51.88
  4. Step 4: Simplify right side
    81.40x = 5,829.24
  5. Step 5: Solve for x
    x = 5,829.24/81.40
  6. Step 6: Final answer
    x = 71.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.