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Finding the Fourth Proportional to 86.71, 119.60 and 72.88

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Solution

The fourth proportional to 86.71, 119.60 and 72.88 is: 100.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.71 : 119.60 = 72.88 : x
  2. Step 2: Convert to fraction form
    86.71/119.60 = 72.88/x
  3. Step 3: Cross multiply
    86.71x = 119.60 × 72.88
  4. Step 4: Simplify right side
    86.71x = 8,716.45
  5. Step 5: Solve for x
    x = 8,716.45/86.71
  6. Step 6: Final answer
    x = 100.52

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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.