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Finding the Fourth Proportional to 159.39, 238.95 and 86.31

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Solution

The fourth proportional to 159.39, 238.95 and 86.31 is: 129.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.39 : 238.95 = 86.31 : x
  2. Step 2: Convert to fraction form
    159.39/238.95 = 86.31/x
  3. Step 3: Cross multiply
    159.39x = 238.95 × 86.31
  4. Step 4: Simplify right side
    159.39x = 20,623.77
  5. Step 5: Solve for x
    x = 20,623.77/159.39
  6. Step 6: Final answer
    x = 129.39

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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.