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Finding the Fourth Proportional to 47.07, 64.74 and 39.78

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Solution

The fourth proportional to 47.07, 64.74 and 39.78 is: 54.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.07 : 64.74 = 39.78 : x
  2. Step 2: Convert to fraction form
    47.07/64.74 = 39.78/x
  3. Step 3: Cross multiply
    47.07x = 64.74 × 39.78
  4. Step 4: Simplify right side
    47.07x = 2,575.36
  5. Step 5: Solve for x
    x = 2,575.36/47.07
  6. Step 6: Final answer
    x = 54.71

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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.