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Finding the Fourth Proportional to 390.62, 585.90 and 147.15

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Solution

The fourth proportional to 390.62, 585.90 and 147.15 is: 220.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.62 : 585.90 = 147.15 : x
  2. Step 2: Convert to fraction form
    390.62/585.90 = 147.15/x
  3. Step 3: Cross multiply
    390.62x = 585.90 × 147.15
  4. Step 4: Simplify right side
    390.62x = 86,215.19
  5. Step 5: Solve for x
    x = 86,215.19/390.62
  6. Step 6: Final answer
    x = 220.71

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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.