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Finding the Fourth Proportional to 828.43, 1,242.28 and 389.81

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Solution

The fourth proportional to 828.43, 1,242.28 and 389.81 is: 584.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.43 : 1,242.28 = 389.81 : x
  2. Step 2: Convert to fraction form
    828.43/1,242.28 = 389.81/x
  3. Step 3: Cross multiply
    828.43x = 1,242.28 × 389.81
  4. Step 4: Simplify right side
    828.43x = 484,246.96
  5. Step 5: Solve for x
    x = 484,246.96/828.43
  6. Step 6: Final answer
    x = 584.54

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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.