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Finding the Fourth Proportional to 855.19, 1,287.31 and 729.91

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Solution

The fourth proportional to 855.19, 1,287.31 and 729.91 is: 1,098.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.19 : 1,287.31 = 729.91 : x
  2. Step 2: Convert to fraction form
    855.19/1,287.31 = 729.91/x
  3. Step 3: Cross multiply
    855.19x = 1,287.31 × 729.91
  4. Step 4: Simplify right side
    855.19x = 939,620.44
  5. Step 5: Solve for x
    x = 939,620.44/855.19
  6. Step 6: Final answer
    x = 1,098.73

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.