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Finding the Fourth Proportional to 739.76, 1,020.80 and 408.16

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Solution

The fourth proportional to 739.76, 1,020.80 and 408.16 is: 563.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.76 : 1,020.80 = 408.16 : x
  2. Step 2: Convert to fraction form
    739.76/1,020.80 = 408.16/x
  3. Step 3: Cross multiply
    739.76x = 1,020.80 × 408.16
  4. Step 4: Simplify right side
    739.76x = 416,649.73
  5. Step 5: Solve for x
    x = 416,649.73/739.76
  6. Step 6: Final answer
    x = 563.22

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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.