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Finding the Fourth Proportional to 102.76, 141.80 and 61.31

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Solution

The fourth proportional to 102.76, 141.80 and 61.31 is: 84.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.76 : 141.80 = 61.31 : x
  2. Step 2: Convert to fraction form
    102.76/141.80 = 61.31/x
  3. Step 3: Cross multiply
    102.76x = 141.80 × 61.31
  4. Step 4: Simplify right side
    102.76x = 8,693.81
  5. Step 5: Solve for x
    x = 8,693.81/102.76
  6. Step 6: Final answer
    x = 84.61

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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.