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Finding the Fourth Proportional to 286.57, 429.88 and 81.16

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Solution

The fourth proportional to 286.57, 429.88 and 81.16 is: 121.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.57 : 429.88 = 81.16 : x
  2. Step 2: Convert to fraction form
    286.57/429.88 = 81.16/x
  3. Step 3: Cross multiply
    286.57x = 429.88 × 81.16
  4. Step 4: Simplify right side
    286.57x = 34,887.78
  5. Step 5: Solve for x
    x = 34,887.78/286.57
  6. Step 6: Final answer
    x = 121.74

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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.