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Finding the Fourth Proportional to 100.49, 138.61 and 79.73

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Solution

The fourth proportional to 100.49, 138.61 and 79.73 is: 109.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.49 : 138.61 = 79.73 : x
  2. Step 2: Convert to fraction form
    100.49/138.61 = 79.73/x
  3. Step 3: Cross multiply
    100.49x = 138.61 × 79.73
  4. Step 4: Simplify right side
    100.49x = 11,052.08
  5. Step 5: Solve for x
    x = 11,052.08/100.49
  6. Step 6: Final answer
    x = 109.98

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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.