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Finding the Fourth Proportional to 84.19, 126.31 and 71.38

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Solution

The fourth proportional to 84.19, 126.31 and 71.38 is: 107.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.19 : 126.31 = 71.38 : x
  2. Step 2: Convert to fraction form
    84.19/126.31 = 71.38/x
  3. Step 3: Cross multiply
    84.19x = 126.31 × 71.38
  4. Step 4: Simplify right side
    84.19x = 9,015.34
  5. Step 5: Solve for x
    x = 9,015.34/84.19
  6. Step 6: Final answer
    x = 107.09

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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.