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Finding the Fourth Proportional to 390.90, 539.62 and 249.17

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Solution

The fourth proportional to 390.90, 539.62 and 249.17 is: 343.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.90 : 539.62 = 249.17 : x
  2. Step 2: Convert to fraction form
    390.90/539.62 = 249.17/x
  3. Step 3: Cross multiply
    390.90x = 539.62 × 249.17
  4. Step 4: Simplify right side
    390.90x = 134,457.12
  5. Step 5: Solve for x
    x = 134,457.12/390.90
  6. Step 6: Final answer
    x = 343.97

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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.