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Finding the Fourth Proportional to 90.70, 126.05 and 89.75

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Solution

The fourth proportional to 90.70, 126.05 and 89.75 is: 124.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.70 : 126.05 = 89.75 : x
  2. Step 2: Convert to fraction form
    90.70/126.05 = 89.75/x
  3. Step 3: Cross multiply
    90.70x = 126.05 × 89.75
  4. Step 4: Simplify right side
    90.70x = 11,312.85
  5. Step 5: Solve for x
    x = 11,312.85/90.70
  6. Step 6: Final answer
    x = 124.73

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.