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Finding the Fourth Proportional to 40.89, 56.39 and 31.70

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Solution

The fourth proportional to 40.89, 56.39 and 31.70 is: 43.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.89 : 56.39 = 31.70 : x
  2. Step 2: Convert to fraction form
    40.89/56.39 = 31.70/x
  3. Step 3: Cross multiply
    40.89x = 56.39 × 31.70
  4. Step 4: Simplify right side
    40.89x = 1,787.56
  5. Step 5: Solve for x
    x = 1,787.56/40.89
  6. Step 6: Final answer
    x = 43.72

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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.