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Finding the Fourth Proportional to 828.69, 1,242.20 and 520.76

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Solution

The fourth proportional to 828.69, 1,242.20 and 520.76 is: 780.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.69 : 1,242.20 = 520.76 : x
  2. Step 2: Convert to fraction form
    828.69/1,242.20 = 520.76/x
  3. Step 3: Cross multiply
    828.69x = 1,242.20 × 520.76
  4. Step 4: Simplify right side
    828.69x = 646,885.47
  5. Step 5: Solve for x
    x = 646,885.47/828.69
  6. Step 6: Final answer
    x = 780.61

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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.