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Finding the Fourth Proportional to 1,271.82, 1,908 and 406.20

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Solution

The fourth proportional to 1,271.82, 1,908 and 406.20 is: 609.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,271.82 : 1,908 = 406.20 : x
  2. Step 2: Convert to fraction form
    1,271.82/1,908 = 406.20/x
  3. Step 3: Cross multiply
    1,271.82x = 1,908 × 406.20
  4. Step 4: Simplify right side
    1,271.82x = 775,029.60
  5. Step 5: Solve for x
    x = 775,029.60/1,271.82
  6. Step 6: Final answer
    x = 609.39

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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.