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Finding the Fourth Proportional to 28.74, 43.20 and 28.31

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Solution

The fourth proportional to 28.74, 43.20 and 28.31 is: 42.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    28.74 : 43.20 = 28.31 : x
  2. Step 2: Convert to fraction form
    28.74/43.20 = 28.31/x
  3. Step 3: Cross multiply
    28.74x = 43.20 × 28.31
  4. Step 4: Simplify right side
    28.74x = 1,222.78
  5. Step 5: Solve for x
    x = 1,222.78/28.74
  6. Step 6: Final answer
    x = 42.55

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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.