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Finding the Fourth Proportional to 159.56, 239.36 and 78.40

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Solution

The fourth proportional to 159.56, 239.36 and 78.40 is: 117.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.56 : 239.36 = 78.40 : x
  2. Step 2: Convert to fraction form
    159.56/239.36 = 78.40/x
  3. Step 3: Cross multiply
    159.56x = 239.36 × 78.40
  4. Step 4: Simplify right side
    159.56x = 18,765.82
  5. Step 5: Solve for x
    x = 18,765.82/159.56
  6. Step 6: Final answer
    x = 117.61

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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.