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Finding the Fourth Proportional to 89.89, 123.78 and 62.21

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Solution

The fourth proportional to 89.89, 123.78 and 62.21 is: 85.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.89 : 123.78 = 62.21 : x
  2. Step 2: Convert to fraction form
    89.89/123.78 = 62.21/x
  3. Step 3: Cross multiply
    89.89x = 123.78 × 62.21
  4. Step 4: Simplify right side
    89.89x = 7,700.35
  5. Step 5: Solve for x
    x = 7,700.35/89.89
  6. Step 6: Final answer
    x = 85.66

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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.