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Finding the Fourth Proportional to 126.80, 174.68 and 89.90

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Solution

The fourth proportional to 126.80, 174.68 and 89.90 is: 123.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.80 : 174.68 = 89.90 : x
  2. Step 2: Convert to fraction form
    126.80/174.68 = 89.90/x
  3. Step 3: Cross multiply
    126.80x = 174.68 × 89.90
  4. Step 4: Simplify right side
    126.80x = 15,703.73
  5. Step 5: Solve for x
    x = 15,703.73/126.80
  6. Step 6: Final answer
    x = 123.85

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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.