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Finding the Fourth Proportional to 89.45, 123.13 and 77.09

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Solution

The fourth proportional to 89.45, 123.13 and 77.09 is: 106.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.45 : 123.13 = 77.09 : x
  2. Step 2: Convert to fraction form
    89.45/123.13 = 77.09/x
  3. Step 3: Cross multiply
    89.45x = 123.13 × 77.09
  4. Step 4: Simplify right side
    89.45x = 9,492.21
  5. Step 5: Solve for x
    x = 9,492.21/89.45
  6. Step 6: Final answer
    x = 106.12

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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.