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Finding the Fourth Proportional to 8.40, 12.60 and 6.39

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Solution

The fourth proportional to 8.40, 12.60 and 6.39 is: 9.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.40 : 12.60 = 6.39 : x
  2. Step 2: Convert to fraction form
    8.40/12.60 = 6.39/x
  3. Step 3: Cross multiply
    8.40x = 12.60 × 6.39
  4. Step 4: Simplify right side
    8.40x = 80.51
  5. Step 5: Solve for x
    x = 80.51/8.40
  6. Step 6: Final answer
    x = 9.59

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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.