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Finding the Fourth Proportional to 159.78, 239.85 and 87.78

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Solution

The fourth proportional to 159.78, 239.85 and 87.78 is: 131.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.78 : 239.85 = 87.78 : x
  2. Step 2: Convert to fraction form
    159.78/239.85 = 87.78/x
  3. Step 3: Cross multiply
    159.78x = 239.85 × 87.78
  4. Step 4: Simplify right side
    159.78x = 21,054.03
  5. Step 5: Solve for x
    x = 21,054.03/159.78
  6. Step 6: Final answer
    x = 131.77

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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.