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Finding the Fourth Proportional to 159.32, 239.12 and 128.80

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Solution

The fourth proportional to 159.32, 239.12 and 128.80 is: 193.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.32 : 239.12 = 128.80 : x
  2. Step 2: Convert to fraction form
    159.32/239.12 = 128.80/x
  3. Step 3: Cross multiply
    159.32x = 239.12 × 128.80
  4. Step 4: Simplify right side
    159.32x = 30,798.66
  5. Step 5: Solve for x
    x = 30,798.66/159.32
  6. Step 6: Final answer
    x = 193.31

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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.