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Finding the Fourth Proportional to 89.39, 123.24 and 77.70

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Solution

The fourth proportional to 89.39, 123.24 and 77.70 is: 107.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.39 : 123.24 = 77.70 : x
  2. Step 2: Convert to fraction form
    89.39/123.24 = 77.70/x
  3. Step 3: Cross multiply
    89.39x = 123.24 × 77.70
  4. Step 4: Simplify right side
    89.39x = 9,575.75
  5. Step 5: Solve for x
    x = 9,575.75/89.39
  6. Step 6: Final answer
    x = 107.13

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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.