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Finding the Fourth Proportional to 50.47, 69.78 and 39.70

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Solution

The fourth proportional to 50.47, 69.78 and 39.70 is: 54.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    50.47 : 69.78 = 39.70 : x
  2. Step 2: Convert to fraction form
    50.47/69.78 = 39.70/x
  3. Step 3: Cross multiply
    50.47x = 69.78 × 39.70
  4. Step 4: Simplify right side
    50.47x = 2,770.27
  5. Step 5: Solve for x
    x = 2,770.27/50.47
  6. Step 6: Final answer
    x = 54.89

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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.