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Finding the Fourth Proportional to 159.57, 239.38 and 128.70

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Solution

The fourth proportional to 159.57, 239.38 and 128.70 is: 193.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.57 : 239.38 = 128.70 : x
  2. Step 2: Convert to fraction form
    159.57/239.38 = 128.70/x
  3. Step 3: Cross multiply
    159.57x = 239.38 × 128.70
  4. Step 4: Simplify right side
    159.57x = 30,807.88
  5. Step 5: Solve for x
    x = 30,807.88/159.57
  6. Step 6: Final answer
    x = 193.07

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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.