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Finding the Fourth Proportional to 86.60, 129.66 and 72.92

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Solution

The fourth proportional to 86.60, 129.66 and 72.92 is: 109.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.60 : 129.66 = 72.92 : x
  2. Step 2: Convert to fraction form
    86.60/129.66 = 72.92/x
  3. Step 3: Cross multiply
    86.60x = 129.66 × 72.92
  4. Step 4: Simplify right side
    86.60x = 9,454.81
  5. Step 5: Solve for x
    x = 9,454.81/86.60
  6. Step 6: Final answer
    x = 109.18

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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.