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Finding the Fourth Proportional to 811.82, 1,120.40 and 497.29

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Solution

The fourth proportional to 811.82, 1,120.40 and 497.29 is: 686.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.82 : 1,120.40 = 497.29 : x
  2. Step 2: Convert to fraction form
    811.82/1,120.40 = 497.29/x
  3. Step 3: Cross multiply
    811.82x = 1,120.40 × 497.29
  4. Step 4: Simplify right side
    811.82x = 557,163.72
  5. Step 5: Solve for x
    x = 557,163.72/811.82
  6. Step 6: Final answer
    x = 686.31

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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.