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Finding the Fourth Proportional to 290.50, 400.90 and 217.18

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Solution

The fourth proportional to 290.50, 400.90 and 217.18 is: 299.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.50 : 400.90 = 217.18 : x
  2. Step 2: Convert to fraction form
    290.50/400.90 = 217.18/x
  3. Step 3: Cross multiply
    290.50x = 400.90 × 217.18
  4. Step 4: Simplify right side
    290.50x = 87,067.46
  5. Step 5: Solve for x
    x = 87,067.46/290.50
  6. Step 6: Final answer
    x = 299.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.