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Finding the Fourth Proportional to 100.32, 137.81 and 87.94

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Solution

The fourth proportional to 100.32, 137.81 and 87.94 is: 120.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.32 : 137.81 = 87.94 : x
  2. Step 2: Convert to fraction form
    100.32/137.81 = 87.94/x
  3. Step 3: Cross multiply
    100.32x = 137.81 × 87.94
  4. Step 4: Simplify right side
    100.32x = 12,119.01
  5. Step 5: Solve for x
    x = 12,119.01/100.32
  6. Step 6: Final answer
    x = 120.80

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.