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Finding the Fourth Proportional to 919.94, 1,380.09 and 342.78

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Solution

The fourth proportional to 919.94, 1,380.09 and 342.78 is: 514.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.94 : 1,380.09 = 342.78 : x
  2. Step 2: Convert to fraction form
    919.94/1,380.09 = 342.78/x
  3. Step 3: Cross multiply
    919.94x = 1,380.09 × 342.78
  4. Step 4: Simplify right side
    919.94x = 473,067.25
  5. Step 5: Solve for x
    x = 473,067.25/919.94
  6. Step 6: Final answer
    x = 514.24

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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.