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Finding the Fourth Proportional to 71.47, 98.63 and 38.72

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Solution

The fourth proportional to 71.47, 98.63 and 38.72 is: 53.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.47 : 98.63 = 38.72 : x
  2. Step 2: Convert to fraction form
    71.47/98.63 = 38.72/x
  3. Step 3: Cross multiply
    71.47x = 98.63 × 38.72
  4. Step 4: Simplify right side
    71.47x = 3,819.48
  5. Step 5: Solve for x
    x = 3,819.48/71.47
  6. Step 6: Final answer
    x = 53.44

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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.