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Finding the Fourth Proportional to 90.20, 123.79 and 80.93

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Solution

The fourth proportional to 90.20, 123.79 and 80.93 is: 111.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.20 : 123.79 = 80.93 : x
  2. Step 2: Convert to fraction form
    90.20/123.79 = 80.93/x
  3. Step 3: Cross multiply
    90.20x = 123.79 × 80.93
  4. Step 4: Simplify right side
    90.20x = 10,018.32
  5. Step 5: Solve for x
    x = 10,018.32/90.20
  6. Step 6: Final answer
    x = 111.07

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.