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Finding the Fourth Proportional to 79.31, 118.32 and 71.64

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Solution

The fourth proportional to 79.31, 118.32 and 71.64 is: 106.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.31 : 118.32 = 71.64 : x
  2. Step 2: Convert to fraction form
    79.31/118.32 = 71.64/x
  3. Step 3: Cross multiply
    79.31x = 118.32 × 71.64
  4. Step 4: Simplify right side
    79.31x = 8,476.44
  5. Step 5: Solve for x
    x = 8,476.44/79.31
  6. Step 6: Final answer
    x = 106.88

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.