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Finding the Fourth Proportional to 13.09, 19.75 and 12.91

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Solution

The fourth proportional to 13.09, 19.75 and 12.91 is: 19.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.09 : 19.75 = 12.91 : x
  2. Step 2: Convert to fraction form
    13.09/19.75 = 12.91/x
  3. Step 3: Cross multiply
    13.09x = 19.75 × 12.91
  4. Step 4: Simplify right side
    13.09x = 254.97
  5. Step 5: Solve for x
    x = 254.97/13.09
  6. Step 6: Final answer
    x = 19.48

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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.