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Finding the Fourth Proportional to 89.75, 123.81 and 65.20

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Solution

The fourth proportional to 89.75, 123.81 and 65.20 is: 89.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.75 : 123.81 = 65.20 : x
  2. Step 2: Convert to fraction form
    89.75/123.81 = 65.20/x
  3. Step 3: Cross multiply
    89.75x = 123.81 × 65.20
  4. Step 4: Simplify right side
    89.75x = 8,072.41
  5. Step 5: Solve for x
    x = 8,072.41/89.75
  6. Step 6: Final answer
    x = 89.94

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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.