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Finding the Fourth Proportional to 47.70, 65.70 and 39.45

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Solution

The fourth proportional to 47.70, 65.70 and 39.45 is: 54.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.70 : 65.70 = 39.45 : x
  2. Step 2: Convert to fraction form
    47.70/65.70 = 39.45/x
  3. Step 3: Cross multiply
    47.70x = 65.70 × 39.45
  4. Step 4: Simplify right side
    47.70x = 2,591.87
  5. Step 5: Solve for x
    x = 2,591.87/47.70
  6. Step 6: Final answer
    x = 54.34

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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.