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Finding the Fourth Proportional to 51.81, 71.47 and 39.49

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Solution

The fourth proportional to 51.81, 71.47 and 39.49 is: 54.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.81 : 71.47 = 39.49 : x
  2. Step 2: Convert to fraction form
    51.81/71.47 = 39.49/x
  3. Step 3: Cross multiply
    51.81x = 71.47 × 39.49
  4. Step 4: Simplify right side
    51.81x = 2,822.15
  5. Step 5: Solve for x
    x = 2,822.15/51.81
  6. Step 6: Final answer
    x = 54.47

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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.