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Finding the Fourth Proportional to 14.31, 21.59 and 13.78

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Solution

The fourth proportional to 14.31, 21.59 and 13.78 is: 20.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    14.31 : 21.59 = 13.78 : x
  2. Step 2: Convert to fraction form
    14.31/21.59 = 13.78/x
  3. Step 3: Cross multiply
    14.31x = 21.59 × 13.78
  4. Step 4: Simplify right side
    14.31x = 297.51
  5. Step 5: Solve for x
    x = 297.51/14.31
  6. Step 6: Final answer
    x = 20.79

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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.