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Finding the Fourth Proportional to 158.86, 238.20 and 85.65

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Solution

The fourth proportional to 158.86, 238.20 and 85.65 is: 128.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.86 : 238.20 = 85.65 : x
  2. Step 2: Convert to fraction form
    158.86/238.20 = 85.65/x
  3. Step 3: Cross multiply
    158.86x = 238.20 × 85.65
  4. Step 4: Simplify right side
    158.86x = 20,401.83
  5. Step 5: Solve for x
    x = 20,401.83/158.86
  6. Step 6: Final answer
    x = 128.43

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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.