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Finding the Fourth Proportional to 85.39, 127.92 and 48.78

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Solution

The fourth proportional to 85.39, 127.92 and 48.78 is: 73.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.39 : 127.92 = 48.78 : x
  2. Step 2: Convert to fraction form
    85.39/127.92 = 48.78/x
  3. Step 3: Cross multiply
    85.39x = 127.92 × 48.78
  4. Step 4: Simplify right side
    85.39x = 6,239.73
  5. Step 5: Solve for x
    x = 6,239.73/85.39
  6. Step 6: Final answer
    x = 73.08

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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.