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Finding the Fourth Proportional to 828.75, 1,242.39 and 308.40

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Solution

The fourth proportional to 828.75, 1,242.39 and 308.40 is: 462.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.75 : 1,242.39 = 308.40 : x
  2. Step 2: Convert to fraction form
    828.75/1,242.39 = 308.40/x
  3. Step 3: Cross multiply
    828.75x = 1,242.39 × 308.40
  4. Step 4: Simplify right side
    828.75x = 383,153.08
  5. Step 5: Solve for x
    x = 383,153.08/828.75
  6. Step 6: Final answer
    x = 462.33

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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.