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Finding the Fourth Proportional to 286.51, 429.70 and 81.09

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Solution

The fourth proportional to 286.51, 429.70 and 81.09 is: 121.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.51 : 429.70 = 81.09 : x
  2. Step 2: Convert to fraction form
    286.51/429.70 = 81.09/x
  3. Step 3: Cross multiply
    286.51x = 429.70 × 81.09
  4. Step 4: Simplify right side
    286.51x = 34,844.37
  5. Step 5: Solve for x
    x = 34,844.37/286.51
  6. Step 6: Final answer
    x = 121.62

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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.