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Finding the Fourth Proportional to 812.79, 1,121.49 and 498.11

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Solution

The fourth proportional to 812.79, 1,121.49 and 498.11 is: 687.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.79 : 1,121.49 = 498.11 : x
  2. Step 2: Convert to fraction form
    812.79/1,121.49 = 498.11/x
  3. Step 3: Cross multiply
    812.79x = 1,121.49 × 498.11
  4. Step 4: Simplify right side
    812.79x = 558,619.78
  5. Step 5: Solve for x
    x = 558,619.78/812.79
  6. Step 6: Final answer
    x = 687.29

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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.