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Finding the Fourth Proportional to 55.90, 77.12 and 39.49

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Solution

The fourth proportional to 55.90, 77.12 and 39.49 is: 54.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.90 : 77.12 = 39.49 : x
  2. Step 2: Convert to fraction form
    55.90/77.12 = 39.49/x
  3. Step 3: Cross multiply
    55.90x = 77.12 × 39.49
  4. Step 4: Simplify right side
    55.90x = 3,045.27
  5. Step 5: Solve for x
    x = 3,045.27/55.90
  6. Step 6: Final answer
    x = 54.48

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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.