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Finding the Fourth Proportional to 71.28, 98.31 and 55.71

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Solution

The fourth proportional to 71.28, 98.31 and 55.71 is: 76.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.28 : 98.31 = 55.71 : x
  2. Step 2: Convert to fraction form
    71.28/98.31 = 55.71/x
  3. Step 3: Cross multiply
    71.28x = 98.31 × 55.71
  4. Step 4: Simplify right side
    71.28x = 5,476.85
  5. Step 5: Solve for x
    x = 5,476.85/71.28
  6. Step 6: Final answer
    x = 76.84

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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.