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Finding the Fourth Proportional to 828.36, 1,242.05 and 280.39

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Solution

The fourth proportional to 828.36, 1,242.05 and 280.39 is: 420.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.36 : 1,242.05 = 280.39 : x
  2. Step 2: Convert to fraction form
    828.36/1,242.05 = 280.39/x
  3. Step 3: Cross multiply
    828.36x = 1,242.05 × 280.39
  4. Step 4: Simplify right side
    828.36x = 348,258.40
  5. Step 5: Solve for x
    x = 348,258.40/828.36
  6. Step 6: Final answer
    x = 420.42

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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.