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Finding the Fourth Proportional to 47.78, 71.30 and 38.10

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Solution

The fourth proportional to 47.78, 71.30 and 38.10 is: 56.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.78 : 71.30 = 38.10 : x
  2. Step 2: Convert to fraction form
    47.78/71.30 = 38.10/x
  3. Step 3: Cross multiply
    47.78x = 71.30 × 38.10
  4. Step 4: Simplify right side
    47.78x = 2,716.34
  5. Step 5: Solve for x
    x = 2,716.34/47.78
  6. Step 6: Final answer
    x = 56.86

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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.