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Finding the Fourth Proportional to 82.15, 112.55 and 81.25

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Solution

The fourth proportional to 82.15, 112.55 and 81.25 is: 111.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.15 : 112.55 = 81.25 : x
  2. Step 2: Convert to fraction form
    82.15/112.55 = 81.25/x
  3. Step 3: Cross multiply
    82.15x = 112.55 × 81.25
  4. Step 4: Simplify right side
    82.15x = 9,144.69
  5. Step 5: Solve for x
    x = 9,144.69/82.15
  6. Step 6: Final answer
    x = 111.32

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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.