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Finding the Fourth Proportional to 19.71, 27.18 and 13.15

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Solution

The fourth proportional to 19.71, 27.18 and 13.15 is: 18.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.71 : 27.18 = 13.15 : x
  2. Step 2: Convert to fraction form
    19.71/27.18 = 13.15/x
  3. Step 3: Cross multiply
    19.71x = 27.18 × 13.15
  4. Step 4: Simplify right side
    19.71x = 357.42
  5. Step 5: Solve for x
    x = 357.42/19.71
  6. Step 6: Final answer
    x = 18.13

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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.