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Finding the Fourth Proportional to 812.96, 1,219.61 and 379.88

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Solution

The fourth proportional to 812.96, 1,219.61 and 379.88 is: 569.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.96 : 1,219.61 = 379.88 : x
  2. Step 2: Convert to fraction form
    812.96/1,219.61 = 379.88/x
  3. Step 3: Cross multiply
    812.96x = 1,219.61 × 379.88
  4. Step 4: Simplify right side
    812.96x = 463,300.30
  5. Step 5: Solve for x
    x = 463,300.30/812.96
  6. Step 6: Final answer
    x = 569.90

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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.