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Finding the Fourth Proportional to 812.88, 1,121.76 and 637.92

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Solution

The fourth proportional to 812.88, 1,121.76 and 637.92 is: 880.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.88 : 1,121.76 = 637.92 : x
  2. Step 2: Convert to fraction form
    812.88/1,121.76 = 637.92/x
  3. Step 3: Cross multiply
    812.88x = 1,121.76 × 637.92
  4. Step 4: Simplify right side
    812.88x = 715,593.14
  5. Step 5: Solve for x
    x = 715,593.14/812.88
  6. Step 6: Final answer
    x = 880.32

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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.