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Finding the Fourth Proportional to 290.20, 400.45 and 159.21

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Solution

The fourth proportional to 290.20, 400.45 and 159.21 is: 219.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.20 : 400.45 = 159.21 : x
  2. Step 2: Convert to fraction form
    290.20/400.45 = 159.21/x
  3. Step 3: Cross multiply
    290.20x = 400.45 × 159.21
  4. Step 4: Simplify right side
    290.20x = 63,756.65
  5. Step 5: Solve for x
    x = 63,756.65/290.20
  6. Step 6: Final answer
    x = 219.70

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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.