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Finding the Fourth Proportional to 84.89, 127.20 and 71.39

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Solution

The fourth proportional to 84.89, 127.20 and 71.39 is: 106.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.89 : 127.20 = 71.39 : x
  2. Step 2: Convert to fraction form
    84.89/127.20 = 71.39/x
  3. Step 3: Cross multiply
    84.89x = 127.20 × 71.39
  4. Step 4: Simplify right side
    84.89x = 9,080.81
  5. Step 5: Solve for x
    x = 9,080.81/84.89
  6. Step 6: Final answer
    x = 106.97

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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.