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Finding the Fourth Proportional to 79.38, 108.95 and 72.90

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Solution

The fourth proportional to 79.38, 108.95 and 72.90 is: 100.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.38 : 108.95 = 72.90 : x
  2. Step 2: Convert to fraction form
    79.38/108.95 = 72.90/x
  3. Step 3: Cross multiply
    79.38x = 108.95 × 72.90
  4. Step 4: Simplify right side
    79.38x = 7,942.46
  5. Step 5: Solve for x
    x = 7,942.46/79.38
  6. Step 6: Final answer
    x = 100.06

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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.