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Finding the Fourth Proportional to 20.78, 31.12 and 14.74

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Solution

The fourth proportional to 20.78, 31.12 and 14.74 is: 22.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.78 : 31.12 = 14.74 : x
  2. Step 2: Convert to fraction form
    20.78/31.12 = 14.74/x
  3. Step 3: Cross multiply
    20.78x = 31.12 × 14.74
  4. Step 4: Simplify right side
    20.78x = 458.71
  5. Step 5: Solve for x
    x = 458.71/20.78
  6. Step 6: Final answer
    x = 22.07

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.