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Finding the Fourth Proportional to 390.56, 585.78 and 130.56

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Solution

The fourth proportional to 390.56, 585.78 and 130.56 is: 195.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.56 : 585.78 = 130.56 : x
  2. Step 2: Convert to fraction form
    390.56/585.78 = 130.56/x
  3. Step 3: Cross multiply
    390.56x = 585.78 × 130.56
  4. Step 4: Simplify right side
    390.56x = 76,481.15
  5. Step 5: Solve for x
    x = 76,481.15/390.56
  6. Step 6: Final answer
    x = 195.82

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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.