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Finding the Fourth Proportional to 812.21, 1,120.53 and 497.21

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Solution

The fourth proportional to 812.21, 1,120.53 and 497.21 is: 685.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.21 : 1,120.53 = 497.21 : x
  2. Step 2: Convert to fraction form
    812.21/1,120.53 = 497.21/x
  3. Step 3: Cross multiply
    812.21x = 1,120.53 × 497.21
  4. Step 4: Simplify right side
    812.21x = 557,141.52
  5. Step 5: Solve for x
    x = 557,141.52/812.21
  6. Step 6: Final answer
    x = 685.96

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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.