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Finding the Fourth Proportional to 55.48, 83.22 and 20.78

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Solution

The fourth proportional to 55.48, 83.22 and 20.78 is: 31.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.48 : 83.22 = 20.78 : x
  2. Step 2: Convert to fraction form
    55.48/83.22 = 20.78/x
  3. Step 3: Cross multiply
    55.48x = 83.22 × 20.78
  4. Step 4: Simplify right side
    55.48x = 1,729.31
  5. Step 5: Solve for x
    x = 1,729.31/55.48
  6. Step 6: Final answer
    x = 31.17

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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.