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Finding the Fourth Proportional to 71.21, 98.28 and 38.47

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Solution

The fourth proportional to 71.21, 98.28 and 38.47 is: 53.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.21 : 98.28 = 38.47 : x
  2. Step 2: Convert to fraction form
    71.21/98.28 = 38.47/x
  3. Step 3: Cross multiply
    71.21x = 98.28 × 38.47
  4. Step 4: Simplify right side
    71.21x = 3,780.38
  5. Step 5: Solve for x
    x = 3,780.38/71.21
  6. Step 6: Final answer
    x = 53.08

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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.