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Finding the Fourth Proportional to 811.09, 1,119.31 and 491.96

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Solution

The fourth proportional to 811.09, 1,119.31 and 491.96 is: 678.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.09 : 1,119.31 = 491.96 : x
  2. Step 2: Convert to fraction form
    811.09/1,119.31 = 491.96/x
  3. Step 3: Cross multiply
    811.09x = 1,119.31 × 491.96
  4. Step 4: Simplify right side
    811.09x = 550,654.18
  5. Step 5: Solve for x
    x = 550,654.18/811.09
  6. Step 6: Final answer
    x = 678.90

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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.