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Finding the Fourth Proportional to 70.68, 105.85 and 61.15

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Solution

The fourth proportional to 70.68, 105.85 and 61.15 is: 91.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.68 : 105.85 = 61.15 : x
  2. Step 2: Convert to fraction form
    70.68/105.85 = 61.15/x
  3. Step 3: Cross multiply
    70.68x = 105.85 × 61.15
  4. Step 4: Simplify right side
    70.68x = 6,472.57
  5. Step 5: Solve for x
    x = 6,472.57/70.68
  6. Step 6: Final answer
    x = 91.58

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.