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Finding the Fourth Proportional to 286.31, 429.40 and 80.90

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Solution

The fourth proportional to 286.31, 429.40 and 80.90 is: 121.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.31 : 429.40 = 80.90 : x
  2. Step 2: Convert to fraction form
    286.31/429.40 = 80.90/x
  3. Step 3: Cross multiply
    286.31x = 429.40 × 80.90
  4. Step 4: Simplify right side
    286.31x = 34,736.11
  5. Step 5: Solve for x
    x = 34,736.11/286.31
  6. Step 6: Final answer
    x = 121.33

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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.