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Finding the Fourth Proportional to 286.86, 430.28 and 81.43

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Solution

The fourth proportional to 286.86, 430.28 and 81.43 is: 122.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.86 : 430.28 = 81.43 : x
  2. Step 2: Convert to fraction form
    286.86/430.28 = 81.43/x
  3. Step 3: Cross multiply
    286.86x = 430.28 × 81.43
  4. Step 4: Simplify right side
    286.86x = 35,037.70
  5. Step 5: Solve for x
    x = 35,037.70/286.86
  6. Step 6: Final answer
    x = 122.14

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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.