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Finding the Fourth Proportional to 756.30, 1,134.42 and 427.20

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Solution

The fourth proportional to 756.30, 1,134.42 and 427.20 is: 640.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.30 : 1,134.42 = 427.20 : x
  2. Step 2: Convert to fraction form
    756.30/1,134.42 = 427.20/x
  3. Step 3: Cross multiply
    756.30x = 1,134.42 × 427.20
  4. Step 4: Simplify right side
    756.30x = 484,624.22
  5. Step 5: Solve for x
    x = 484,624.22/756.30
  6. Step 6: Final answer
    x = 640.78

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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.