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Finding the Fourth Proportional to 8.51, 12.75 and 5.12

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Solution

The fourth proportional to 8.51, 12.75 and 5.12 is: 7.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.51 : 12.75 = 5.12 : x
  2. Step 2: Convert to fraction form
    8.51/12.75 = 5.12/x
  3. Step 3: Cross multiply
    8.51x = 12.75 × 5.12
  4. Step 4: Simplify right side
    8.51x = 65.22
  5. Step 5: Solve for x
    x = 65.22/8.51
  6. Step 6: Final answer
    x = 7.67

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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.