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Finding the Fourth Proportional to 8.40, 12.66 and 8.20

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Solution

The fourth proportional to 8.40, 12.66 and 8.20 is: 12.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.40 : 12.66 = 8.20 : x
  2. Step 2: Convert to fraction form
    8.40/12.66 = 8.20/x
  3. Step 3: Cross multiply
    8.40x = 12.66 × 8.20
  4. Step 4: Simplify right side
    8.40x = 103.81
  5. Step 5: Solve for x
    x = 103.81/8.40
  6. Step 6: Final answer
    x = 12.36

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.