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Finding the Fourth Proportional to 79.20, 108.78 and 73.20

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Solution

The fourth proportional to 79.20, 108.78 and 73.20 is: 100.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.20 : 108.78 = 73.20 : x
  2. Step 2: Convert to fraction form
    79.20/108.78 = 73.20/x
  3. Step 3: Cross multiply
    79.20x = 108.78 × 73.20
  4. Step 4: Simplify right side
    79.20x = 7,962.70
  5. Step 5: Solve for x
    x = 7,962.70/79.20
  6. Step 6: Final answer
    x = 100.54

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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.