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Finding the Fourth Proportional to 840.62, 1,259.30 and 408.08

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Solution

The fourth proportional to 840.62, 1,259.30 and 408.08 is: 611.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.62 : 1,259.30 = 408.08 : x
  2. Step 2: Convert to fraction form
    840.62/1,259.30 = 408.08/x
  3. Step 3: Cross multiply
    840.62x = 1,259.30 × 408.08
  4. Step 4: Simplify right side
    840.62x = 513,889.87
  5. Step 5: Solve for x
    x = 513,889.87/840.62
  6. Step 6: Final answer
    x = 611.33

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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.