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Finding the Fourth Proportional to 8.56, 12.85 and 5

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Solution

The fourth proportional to 8.56, 12.85 and 5 is: 7.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.56 : 12.85 = 5 : x
  2. Step 2: Convert to fraction form
    8.56/12.85 = 5/x
  3. Step 3: Cross multiply
    8.56x = 12.85 × 5
  4. Step 4: Simplify right side
    8.56x = 64.25
  5. Step 5: Solve for x
    x = 64.25/8.56
  6. Step 6: Final answer
    x = 7.51

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.