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Finding the Fourth Proportional to 828.40, 1,143.12 and 479.12

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Solution

The fourth proportional to 828.40, 1,143.12 and 479.12 is: 661.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.40 : 1,143.12 = 479.12 : x
  2. Step 2: Convert to fraction form
    828.40/1,143.12 = 479.12/x
  3. Step 3: Cross multiply
    828.40x = 1,143.12 × 479.12
  4. Step 4: Simplify right side
    828.40x = 547,691.65
  5. Step 5: Solve for x
    x = 547,691.65/828.40
  6. Step 6: Final answer
    x = 661.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.