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Finding the Fourth Proportional to 159.38, 238.80 and 87.20

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Solution

The fourth proportional to 159.38, 238.80 and 87.20 is: 130.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.38 : 238.80 = 87.20 : x
  2. Step 2: Convert to fraction form
    159.38/238.80 = 87.20/x
  3. Step 3: Cross multiply
    159.38x = 238.80 × 87.20
  4. Step 4: Simplify right side
    159.38x = 20,823.36
  5. Step 5: Solve for x
    x = 20,823.36/159.38
  6. Step 6: Final answer
    x = 130.65

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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.