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Finding the Fourth Proportional to 828.10, 1,240.80 and 609.40

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Solution

The fourth proportional to 828.10, 1,240.80 and 609.40 is: 913.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.10 : 1,240.80 = 609.40 : x
  2. Step 2: Convert to fraction form
    828.10/1,240.80 = 609.40/x
  3. Step 3: Cross multiply
    828.10x = 1,240.80 × 609.40
  4. Step 4: Simplify right side
    828.10x = 756,143.52
  5. Step 5: Solve for x
    x = 756,143.52/828.10
  6. Step 6: Final answer
    x = 913.11

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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.