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Finding the Fourth Proportional to 31.57, 43.40 and 28.08

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Solution

The fourth proportional to 31.57, 43.40 and 28.08 is: 38.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.57 : 43.40 = 28.08 : x
  2. Step 2: Convert to fraction form
    31.57/43.40 = 28.08/x
  3. Step 3: Cross multiply
    31.57x = 43.40 × 28.08
  4. Step 4: Simplify right side
    31.57x = 1,218.74
  5. Step 5: Solve for x
    x = 1,218.74/31.57
  6. Step 6: Final answer
    x = 38.61

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.