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Finding the Fourth Proportional to 390.69, 585.32 and 198.09

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Solution

The fourth proportional to 390.69, 585.32 and 198.09 is: 296.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.69 : 585.32 = 198.09 : x
  2. Step 2: Convert to fraction form
    390.69/585.32 = 198.09/x
  3. Step 3: Cross multiply
    390.69x = 585.32 × 198.09
  4. Step 4: Simplify right side
    390.69x = 115,945.05
  5. Step 5: Solve for x
    x = 115,945.05/390.69
  6. Step 6: Final answer
    x = 296.77

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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.