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Finding the Fourth Proportional to 812.26, 1,120.18 and 687.79

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Solution

The fourth proportional to 812.26, 1,120.18 and 687.79 is: 948.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.26 : 1,120.18 = 687.79 : x
  2. Step 2: Convert to fraction form
    812.26/1,120.18 = 687.79/x
  3. Step 3: Cross multiply
    812.26x = 1,120.18 × 687.79
  4. Step 4: Simplify right side
    812.26x = 770,448.60
  5. Step 5: Solve for x
    x = 770,448.60/812.26
  6. Step 6: Final answer
    x = 948.52

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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.