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Finding the Fourth Proportional to 84.65, 126.75 and 71.79

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Solution

The fourth proportional to 84.65, 126.75 and 71.79 is: 107.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.65 : 126.75 = 71.79 : x
  2. Step 2: Convert to fraction form
    84.65/126.75 = 71.79/x
  3. Step 3: Cross multiply
    84.65x = 126.75 × 71.79
  4. Step 4: Simplify right side
    84.65x = 9,098.77
  5. Step 5: Solve for x
    x = 9,098.77/84.65
  6. Step 6: Final answer
    x = 107.49

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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.