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Finding the Fourth Proportional to 79.10, 109.17 and 54.21

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Solution

The fourth proportional to 79.10, 109.17 and 54.21 is: 74.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.10 : 109.17 = 54.21 : x
  2. Step 2: Convert to fraction form
    79.10/109.17 = 54.21/x
  3. Step 3: Cross multiply
    79.10x = 109.17 × 54.21
  4. Step 4: Simplify right side
    79.10x = 5,918.11
  5. Step 5: Solve for x
    x = 5,918.11/79.10
  6. Step 6: Final answer
    x = 74.82

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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.