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Finding the Fourth Proportional to 55.31, 76.19 and 38.90

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Solution

The fourth proportional to 55.31, 76.19 and 38.90 is: 53.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.31 : 76.19 = 38.90 : x
  2. Step 2: Convert to fraction form
    55.31/76.19 = 38.90/x
  3. Step 3: Cross multiply
    55.31x = 76.19 × 38.90
  4. Step 4: Simplify right side
    55.31x = 2,963.22
  5. Step 5: Solve for x
    x = 2,963.22/55.31
  6. Step 6: Final answer
    x = 53.58

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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.