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Finding the Fourth Proportional to 79.72, 119.44 and 66.88

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Solution

The fourth proportional to 79.72, 119.44 and 66.88 is: 100.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.72 : 119.44 = 66.88 : x
  2. Step 2: Convert to fraction form
    79.72/119.44 = 66.88/x
  3. Step 3: Cross multiply
    79.72x = 119.44 × 66.88
  4. Step 4: Simplify right side
    79.72x = 7,988.15
  5. Step 5: Solve for x
    x = 7,988.15/79.72
  6. Step 6: Final answer
    x = 100.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.