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Finding the Fourth Proportional to 390.29, 585.18 and 243.68

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Solution

The fourth proportional to 390.29, 585.18 and 243.68 is: 365.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.29 : 585.18 = 243.68 : x
  2. Step 2: Convert to fraction form
    390.29/585.18 = 243.68/x
  3. Step 3: Cross multiply
    390.29x = 585.18 × 243.68
  4. Step 4: Simplify right side
    390.29x = 142,593.74
  5. Step 5: Solve for x
    x = 142,593.74/390.29
  6. Step 6: Final answer
    x = 365.36

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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.