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Finding the Fourth Proportional to 828.60, 1,243.10 and 280.81

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Solution

The fourth proportional to 828.60, 1,243.10 and 280.81 is: 421.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.60 : 1,243.10 = 280.81 : x
  2. Step 2: Convert to fraction form
    828.60/1,243.10 = 280.81/x
  3. Step 3: Cross multiply
    828.60x = 1,243.10 × 280.81
  4. Step 4: Simplify right side
    828.60x = 349,074.91
  5. Step 5: Solve for x
    x = 349,074.91/828.60
  6. Step 6: Final answer
    x = 421.28

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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.