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Finding the Fourth Proportional to 81.07, 111.65 and 74.18

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Solution

The fourth proportional to 81.07, 111.65 and 74.18 is: 102.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.07 : 111.65 = 74.18 : x
  2. Step 2: Convert to fraction form
    81.07/111.65 = 74.18/x
  3. Step 3: Cross multiply
    81.07x = 111.65 × 74.18
  4. Step 4: Simplify right side
    81.07x = 8,282.11
  5. Step 5: Solve for x
    x = 8,282.11/81.07
  6. Step 6: Final answer
    x = 102.16

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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.