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Finding the Fourth Proportional to 811.73, 1,119.79 and 780.29

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Solution

The fourth proportional to 811.73, 1,119.79 and 780.29 is: 1,076.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.73 : 1,119.79 = 780.29 : x
  2. Step 2: Convert to fraction form
    811.73/1,119.79 = 780.29/x
  3. Step 3: Cross multiply
    811.73x = 1,119.79 × 780.29
  4. Step 4: Simplify right side
    811.73x = 873,766.81
  5. Step 5: Solve for x
    x = 873,766.81/811.73
  6. Step 6: Final answer
    x = 1,076.42

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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.