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Finding the Fourth Proportional to 8.21, 11.39 and 8

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Solution

The fourth proportional to 8.21, 11.39 and 8 is: 11.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.21 : 11.39 = 8 : x
  2. Step 2: Convert to fraction form
    8.21/11.39 = 8/x
  3. Step 3: Cross multiply
    8.21x = 11.39 × 8
  4. Step 4: Simplify right side
    8.21x = 91.12
  5. Step 5: Solve for x
    x = 91.12/8.21
  6. Step 6: Final answer
    x = 11.10

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.