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Finding the Fourth Proportional to 826.20, 1,238.76 and 393.12

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Solution

The fourth proportional to 826.20, 1,238.76 and 393.12 is: 589.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    826.20 : 1,238.76 = 393.12 : x
  2. Step 2: Convert to fraction form
    826.20/1,238.76 = 393.12/x
  3. Step 3: Cross multiply
    826.20x = 1,238.76 × 393.12
  4. Step 4: Simplify right side
    826.20x = 486,981.33
  5. Step 5: Solve for x
    x = 486,981.33/826.20
  6. Step 6: Final answer
    x = 589.42

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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.