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Finding the Fourth Proportional to 857.82, 1,288.25 and 789.20

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Solution

The fourth proportional to 857.82, 1,288.25 and 789.20 is: 1,185.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.82 : 1,288.25 = 789.20 : x
  2. Step 2: Convert to fraction form
    857.82/1,288.25 = 789.20/x
  3. Step 3: Cross multiply
    857.82x = 1,288.25 × 789.20
  4. Step 4: Simplify right side
    857.82x = 1,016,676.51
  5. Step 5: Solve for x
    x = 1,016,676.51/857.82
  6. Step 6: Final answer
    x = 1,185.19

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.