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Finding the Fourth Proportional to 90.88, 125.49 and 61.90

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Solution

The fourth proportional to 90.88, 125.49 and 61.90 is: 85.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.88 : 125.49 = 61.90 : x
  2. Step 2: Convert to fraction form
    90.88/125.49 = 61.90/x
  3. Step 3: Cross multiply
    90.88x = 125.49 × 61.90
  4. Step 4: Simplify right side
    90.88x = 7,767.83
  5. Step 5: Solve for x
    x = 7,767.83/90.88
  6. Step 6: Final answer
    x = 85.47

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.