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Finding the Fourth Proportional to 15.16, 20.91 and 8.69

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Solution

The fourth proportional to 15.16, 20.91 and 8.69 is: 11.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.16 : 20.91 = 8.69 : x
  2. Step 2: Convert to fraction form
    15.16/20.91 = 8.69/x
  3. Step 3: Cross multiply
    15.16x = 20.91 × 8.69
  4. Step 4: Simplify right side
    15.16x = 181.60
  5. Step 5: Solve for x
    x = 181.60/15.16
  6. Step 6: Final answer
    x = 11.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.