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Finding the Fourth Proportional to 55.15, 82.38 and 38.78

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Solution

The fourth proportional to 55.15, 82.38 and 38.78 is: 57.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.15 : 82.38 = 38.78 : x
  2. Step 2: Convert to fraction form
    55.15/82.38 = 38.78/x
  3. Step 3: Cross multiply
    55.15x = 82.38 × 38.78
  4. Step 4: Simplify right side
    55.15x = 3,194.74
  5. Step 5: Solve for x
    x = 3,194.74/55.15
  6. Step 6: Final answer
    x = 57.93

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.