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Finding the Fourth Proportional to 390.35, 538.83 and 290.61

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Solution

The fourth proportional to 390.35, 538.83 and 290.61 is: 401.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.35 : 538.83 = 290.61 : x
  2. Step 2: Convert to fraction form
    390.35/538.83 = 290.61/x
  3. Step 3: Cross multiply
    390.35x = 538.83 × 290.61
  4. Step 4: Simplify right side
    390.35x = 156,589.39
  5. Step 5: Solve for x
    x = 156,589.39/390.35
  6. Step 6: Final answer
    x = 401.15

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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.