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Finding the Fourth Proportional to 739.61, 1,020.64 and 408.05

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Solution

The fourth proportional to 739.61, 1,020.64 and 408.05 is: 563.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.61 : 1,020.64 = 408.05 : x
  2. Step 2: Convert to fraction form
    739.61/1,020.64 = 408.05/x
  3. Step 3: Cross multiply
    739.61x = 1,020.64 × 408.05
  4. Step 4: Simplify right side
    739.61x = 416,472.15
  5. Step 5: Solve for x
    x = 416,472.15/739.61
  6. Step 6: Final answer
    x = 563.10

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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.