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Finding the Fourth Proportional to 919.30, 1,379.03 and 261.18

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Solution

The fourth proportional to 919.30, 1,379.03 and 261.18 is: 391.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.30 : 1,379.03 = 261.18 : x
  2. Step 2: Convert to fraction form
    919.30/1,379.03 = 261.18/x
  3. Step 3: Cross multiply
    919.30x = 1,379.03 × 261.18
  4. Step 4: Simplify right side
    919.30x = 360,168.58
  5. Step 5: Solve for x
    x = 360,168.58/919.30
  6. Step 6: Final answer
    x = 391.79

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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.