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Finding the Fourth Proportional to 82.10, 112.70 and 72.69

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Solution

The fourth proportional to 82.10, 112.70 and 72.69 is: 99.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.10 : 112.70 = 72.69 : x
  2. Step 2: Convert to fraction form
    82.10/112.70 = 72.69/x
  3. Step 3: Cross multiply
    82.10x = 112.70 × 72.69
  4. Step 4: Simplify right side
    82.10x = 8,192.16
  5. Step 5: Solve for x
    x = 8,192.16/82.10
  6. Step 6: Final answer
    x = 99.78

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.