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Finding the Fourth Proportional to 919.10, 1,268.39 and 520.85

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Solution

The fourth proportional to 919.10, 1,268.39 and 520.85 is: 718.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.10 : 1,268.39 = 520.85 : x
  2. Step 2: Convert to fraction form
    919.10/1,268.39 = 520.85/x
  3. Step 3: Cross multiply
    919.10x = 1,268.39 × 520.85
  4. Step 4: Simplify right side
    919.10x = 660,645.40
  5. Step 5: Solve for x
    x = 660,645.40/919.10
  6. Step 6: Final answer
    x = 718.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.