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Finding the Fourth Proportional to 14.78, 20.42 and 14.31

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Solution

The fourth proportional to 14.78, 20.42 and 14.31 is: 19.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    14.78 : 20.42 = 14.31 : x
  2. Step 2: Convert to fraction form
    14.78/20.42 = 14.31/x
  3. Step 3: Cross multiply
    14.78x = 20.42 × 14.31
  4. Step 4: Simplify right side
    14.78x = 292.14
  5. Step 5: Solve for x
    x = 292.14/14.78
  6. Step 6: Final answer
    x = 19.77

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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.