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Finding the Fourth Proportional to 1,380.58, 2,070.87 and 406.78

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Solution

The fourth proportional to 1,380.58, 2,070.87 and 406.78 is: 610.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.58 : 2,070.87 = 406.78 : x
  2. Step 2: Convert to fraction form
    1,380.58/2,070.87 = 406.78/x
  3. Step 3: Cross multiply
    1,380.58x = 2,070.87 × 406.78
  4. Step 4: Simplify right side
    1,380.58x = 842,388.50
  5. Step 5: Solve for x
    x = 842,388.50/1,380.58
  6. Step 6: Final answer
    x = 610.17

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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.