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Finding the Fourth Proportional to 390.61, 585.78 and 159.49

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Solution

The fourth proportional to 390.61, 585.78 and 159.49 is: 239.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.61 : 585.78 = 159.49 : x
  2. Step 2: Convert to fraction form
    390.61/585.78 = 159.49/x
  3. Step 3: Cross multiply
    390.61x = 585.78 × 159.49
  4. Step 4: Simplify right side
    390.61x = 93,426.05
  5. Step 5: Solve for x
    x = 93,426.05/390.61
  6. Step 6: Final answer
    x = 239.18

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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.