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Finding the Fourth Proportional to 79.11, 109.21 and 61.58

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Solution

The fourth proportional to 79.11, 109.21 and 61.58 is: 85.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.11 : 109.21 = 61.58 : x
  2. Step 2: Convert to fraction form
    79.11/109.21 = 61.58/x
  3. Step 3: Cross multiply
    79.11x = 109.21 × 61.58
  4. Step 4: Simplify right side
    79.11x = 6,725.15
  5. Step 5: Solve for x
    x = 6,725.15/79.11
  6. Step 6: Final answer
    x = 85.01

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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.