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Finding the Fourth Proportional to 85.34, 127.50 and 80.90

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Solution

The fourth proportional to 85.34, 127.50 and 80.90 is: 120.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.34 : 127.50 = 80.90 : x
  2. Step 2: Convert to fraction form
    85.34/127.50 = 80.90/x
  3. Step 3: Cross multiply
    85.34x = 127.50 × 80.90
  4. Step 4: Simplify right side
    85.34x = 10,314.75
  5. Step 5: Solve for x
    x = 10,314.75/85.34
  6. Step 6: Final answer
    x = 120.87

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.