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Finding the Fourth Proportional to 71.56, 98.86 and 61.31

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Solution

The fourth proportional to 71.56, 98.86 and 61.31 is: 84.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.56 : 98.86 = 61.31 : x
  2. Step 2: Convert to fraction form
    71.56/98.86 = 61.31/x
  3. Step 3: Cross multiply
    71.56x = 98.86 × 61.31
  4. Step 4: Simplify right side
    71.56x = 6,060.46
  5. Step 5: Solve for x
    x = 6,060.46/71.56
  6. Step 6: Final answer
    x = 84.69

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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.