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Finding the Fourth Proportional to 1,380.81, 2,070.81 and 406.79

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Solution

The fourth proportional to 1,380.81, 2,070.81 and 406.79 is: 610.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.81 : 2,070.81 = 406.79 : x
  2. Step 2: Convert to fraction form
    1,380.81/2,070.81 = 406.79/x
  3. Step 3: Cross multiply
    1,380.81x = 2,070.81 × 406.79
  4. Step 4: Simplify right side
    1,380.81x = 842,374.45
  5. Step 5: Solve for x
    x = 842,374.45/1,380.81
  6. Step 6: Final answer
    x = 610.06

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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.