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Finding the Fourth Proportional to 842.09, 1,261.42 and 686.47

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Solution

The fourth proportional to 842.09, 1,261.42 and 686.47 is: 1,028.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.09 : 1,261.42 = 686.47 : x
  2. Step 2: Convert to fraction form
    842.09/1,261.42 = 686.47/x
  3. Step 3: Cross multiply
    842.09x = 1,261.42 × 686.47
  4. Step 4: Simplify right side
    842.09x = 865,923.56
  5. Step 5: Solve for x
    x = 865,923.56/842.09
  6. Step 6: Final answer
    x = 1,028.30

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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.