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Finding the Fourth Proportional to 79.72, 110.09 and 72.43

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Solution

The fourth proportional to 79.72, 110.09 and 72.43 is: 100.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.72 : 110.09 = 72.43 : x
  2. Step 2: Convert to fraction form
    79.72/110.09 = 72.43/x
  3. Step 3: Cross multiply
    79.72x = 110.09 × 72.43
  4. Step 4: Simplify right side
    79.72x = 7,972.91
  5. Step 5: Solve for x
    x = 7,972.91/79.72
  6. Step 6: Final answer
    x = 100.02

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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.