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Finding the Fourth Proportional to 15.43, 21.31 and 13.69

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Solution

The fourth proportional to 15.43, 21.31 and 13.69 is: 18.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.43 : 21.31 = 13.69 : x
  2. Step 2: Convert to fraction form
    15.43/21.31 = 13.69/x
  3. Step 3: Cross multiply
    15.43x = 21.31 × 13.69
  4. Step 4: Simplify right side
    15.43x = 291.86
  5. Step 5: Solve for x
    x = 291.86/15.43
  6. Step 6: Final answer
    x = 18.92

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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.