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Finding the Fourth Proportional to 919.40, 1,379.12 and 303.20

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Solution

The fourth proportional to 919.40, 1,379.12 and 303.20 is: 454.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.40 : 1,379.12 = 303.20 : x
  2. Step 2: Convert to fraction form
    919.40/1,379.12 = 303.20/x
  3. Step 3: Cross multiply
    919.40x = 1,379.12 × 303.20
  4. Step 4: Simplify right side
    919.40x = 418,149.18
  5. Step 5: Solve for x
    x = 418,149.18/919.40
  6. Step 6: Final answer
    x = 454.81

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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.