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Finding the Fourth Proportional to 31.32, 43.22 and 20.40

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Solution

The fourth proportional to 31.32, 43.22 and 20.40 is: 28.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.32 : 43.22 = 20.40 : x
  2. Step 2: Convert to fraction form
    31.32/43.22 = 20.40/x
  3. Step 3: Cross multiply
    31.32x = 43.22 × 20.40
  4. Step 4: Simplify right side
    31.32x = 881.59
  5. Step 5: Solve for x
    x = 881.59/31.32
  6. Step 6: Final answer
    x = 28.15

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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.