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Finding the Fourth Proportional to 812.27, 1,218.17 and 318.65

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Solution

The fourth proportional to 812.27, 1,218.17 and 318.65 is: 477.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.27 : 1,218.17 = 318.65 : x
  2. Step 2: Convert to fraction form
    812.27/1,218.17 = 318.65/x
  3. Step 3: Cross multiply
    812.27x = 1,218.17 × 318.65
  4. Step 4: Simplify right side
    812.27x = 388,162.19
  5. Step 5: Solve for x
    x = 388,162.19/812.27
  6. Step 6: Final answer
    x = 477.88

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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.