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Finding the Fourth Proportional to 159.21, 239.05 and 90.87

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Solution

The fourth proportional to 159.21, 239.05 and 90.87 is: 136.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.21 : 239.05 = 90.87 : x
  2. Step 2: Convert to fraction form
    159.21/239.05 = 90.87/x
  3. Step 3: Cross multiply
    159.21x = 239.05 × 90.87
  4. Step 4: Simplify right side
    159.21x = 21,722.47
  5. Step 5: Solve for x
    x = 21,722.47/159.21
  6. Step 6: Final answer
    x = 136.44

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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.