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Finding the Fourth Proportional to 86.18, 118.89 and 66.53

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Solution

The fourth proportional to 86.18, 118.89 and 66.53 is: 91.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.18 : 118.89 = 66.53 : x
  2. Step 2: Convert to fraction form
    86.18/118.89 = 66.53/x
  3. Step 3: Cross multiply
    86.18x = 118.89 × 66.53
  4. Step 4: Simplify right side
    86.18x = 7,909.16
  5. Step 5: Solve for x
    x = 7,909.16/86.18
  6. Step 6: Final answer
    x = 91.78

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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.