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Finding the Fourth Proportional to 739.72, 1,020.79 and 408.12

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Solution

The fourth proportional to 739.72, 1,020.79 and 408.12 is: 563.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.72 : 1,020.79 = 408.12 : x
  2. Step 2: Convert to fraction form
    739.72/1,020.79 = 408.12/x
  3. Step 3: Cross multiply
    739.72x = 1,020.79 × 408.12
  4. Step 4: Simplify right side
    739.72x = 416,602.77
  5. Step 5: Solve for x
    x = 416,602.77/739.72
  6. Step 6: Final answer
    x = 563.19

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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.