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Finding the Fourth Proportional to 79.70, 109.96 and 55.15

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Solution

The fourth proportional to 79.70, 109.96 and 55.15 is: 76.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.70 : 109.96 = 55.15 : x
  2. Step 2: Convert to fraction form
    79.70/109.96 = 55.15/x
  3. Step 3: Cross multiply
    79.70x = 109.96 × 55.15
  4. Step 4: Simplify right side
    79.70x = 6,064.29
  5. Step 5: Solve for x
    x = 6,064.29/79.70
  6. Step 6: Final answer
    x = 76.09

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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.