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Finding the Fourth Proportional to 8.90, 13.25 and 8.81

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Solution

The fourth proportional to 8.90, 13.25 and 8.81 is: 13.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.90 : 13.25 = 8.81 : x
  2. Step 2: Convert to fraction form
    8.90/13.25 = 8.81/x
  3. Step 3: Cross multiply
    8.90x = 13.25 × 8.81
  4. Step 4: Simplify right side
    8.90x = 116.69
  5. Step 5: Solve for x
    x = 116.69/8.90
  6. Step 6: Final answer
    x = 13.11

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.