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Finding the Fourth Proportional to 79.31, 109.38 and 62.91

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Solution

The fourth proportional to 79.31, 109.38 and 62.91 is: 86.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.31 : 109.38 = 62.91 : x
  2. Step 2: Convert to fraction form
    79.31/109.38 = 62.91/x
  3. Step 3: Cross multiply
    79.31x = 109.38 × 62.91
  4. Step 4: Simplify right side
    79.31x = 6,881.10
  5. Step 5: Solve for x
    x = 6,881.10/79.31
  6. Step 6: Final answer
    x = 86.77

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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.