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Finding the Fourth Proportional to 71.65, 107.42 and 28.31

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Solution

The fourth proportional to 71.65, 107.42 and 28.31 is: 42.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.65 : 107.42 = 28.31 : x
  2. Step 2: Convert to fraction form
    71.65/107.42 = 28.31/x
  3. Step 3: Cross multiply
    71.65x = 107.42 × 28.31
  4. Step 4: Simplify right side
    71.65x = 3,040.99
  5. Step 5: Solve for x
    x = 3,040.99/71.65
  6. Step 6: Final answer
    x = 42.44

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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.