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Finding the Fourth Proportional to 71.45, 98.61 and 38.71

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Solution

The fourth proportional to 71.45, 98.61 and 38.71 is: 53.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.45 : 98.61 = 38.71 : x
  2. Step 2: Convert to fraction form
    71.45/98.61 = 38.71/x
  3. Step 3: Cross multiply
    71.45x = 98.61 × 38.71
  4. Step 4: Simplify right side
    71.45x = 3,816.87
  5. Step 5: Solve for x
    x = 3,816.87/71.45
  6. Step 6: Final answer
    x = 53.42

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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.