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Finding the Fourth Proportional to 48.78, 67.28 and 31.31

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Solution

The fourth proportional to 48.78, 67.28 and 31.31 is: 43.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    48.78 : 67.28 = 31.31 : x
  2. Step 2: Convert to fraction form
    48.78/67.28 = 31.31/x
  3. Step 3: Cross multiply
    48.78x = 67.28 × 31.31
  4. Step 4: Simplify right side
    48.78x = 2,106.78
  5. Step 5: Solve for x
    x = 2,106.78/48.78
  6. Step 6: Final answer
    x = 43.19

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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.