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Finding the Fourth Proportional to 49.78, 68.72 and 31.39

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Solution

The fourth proportional to 49.78, 68.72 and 31.39 is: 43.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    49.78 : 68.72 = 31.39 : x
  2. Step 2: Convert to fraction form
    49.78/68.72 = 31.39/x
  3. Step 3: Cross multiply
    49.78x = 68.72 × 31.39
  4. Step 4: Simplify right side
    49.78x = 2,156.79
  5. Step 5: Solve for x
    x = 2,156.79/49.78
  6. Step 6: Final answer
    x = 43.33

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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.