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Finding the Fourth Proportional to 71.15, 98.19 and 39.64

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Solution

The fourth proportional to 71.15, 98.19 and 39.64 is: 54.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.15 : 98.19 = 39.64 : x
  2. Step 2: Convert to fraction form
    71.15/98.19 = 39.64/x
  3. Step 3: Cross multiply
    71.15x = 98.19 × 39.64
  4. Step 4: Simplify right side
    71.15x = 3,892.25
  5. Step 5: Solve for x
    x = 3,892.25/71.15
  6. Step 6: Final answer
    x = 54.70

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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.