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Finding the Fourth Proportional to 840.99, 1,259.86 and 408.45

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Solution

The fourth proportional to 840.99, 1,259.86 and 408.45 is: 611.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.99 : 1,259.86 = 408.45 : x
  2. Step 2: Convert to fraction form
    840.99/1,259.86 = 408.45/x
  3. Step 3: Cross multiply
    840.99x = 1,259.86 × 408.45
  4. Step 4: Simplify right side
    840.99x = 514,589.82
  5. Step 5: Solve for x
    x = 514,589.82/840.99
  6. Step 6: Final answer
    x = 611.89

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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.