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Finding the Fourth Proportional to 89.00, 122.79 and 55.78

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Solution

The fourth proportional to 89.00, 122.79 and 55.78 is: 76.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.00 : 122.79 = 55.78 : x
  2. Step 2: Convert to fraction form
    89.00/122.79 = 55.78/x
  3. Step 3: Cross multiply
    89.00x = 122.79 × 55.78
  4. Step 4: Simplify right side
    89.00x = 6,848.95
  5. Step 5: Solve for x
    x = 6,848.95/89.00
  6. Step 6: Final answer
    x = 76.96

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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.