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Finding the Fourth Proportional to 47.79, 71.72 and 28.56

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Solution

The fourth proportional to 47.79, 71.72 and 28.56 is: 42.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.79 : 71.72 = 28.56 : x
  2. Step 2: Convert to fraction form
    47.79/71.72 = 28.56/x
  3. Step 3: Cross multiply
    47.79x = 71.72 × 28.56
  4. Step 4: Simplify right side
    47.79x = 2,048.18
  5. Step 5: Solve for x
    x = 2,048.18/47.79
  6. Step 6: Final answer
    x = 42.86

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.