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Finding the Fourth Proportional to 287.41, 431.05 and 81.97

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Solution

The fourth proportional to 287.41, 431.05 and 81.97 is: 122.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.41 : 431.05 = 81.97 : x
  2. Step 2: Convert to fraction form
    287.41/431.05 = 81.97/x
  3. Step 3: Cross multiply
    287.41x = 431.05 × 81.97
  4. Step 4: Simplify right side
    287.41x = 35,332.76
  5. Step 5: Solve for x
    x = 35,332.76/287.41
  6. Step 6: Final answer
    x = 122.94

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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.