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Finding the Fourth Proportional to 81.60, 112.50 and 65.18

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Solution

The fourth proportional to 81.60, 112.50 and 65.18 is: 89.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.60 : 112.50 = 65.18 : x
  2. Step 2: Convert to fraction form
    81.60/112.50 = 65.18/x
  3. Step 3: Cross multiply
    81.60x = 112.50 × 65.18
  4. Step 4: Simplify right side
    81.60x = 7,332.19
  5. Step 5: Solve for x
    x = 7,332.19/81.60
  6. Step 6: Final answer
    x = 89.86

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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.