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Finding the Fourth Proportional to 842.78, 1,262.42 and 781.26

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Solution

The fourth proportional to 842.78, 1,262.42 and 781.26 is: 1,170.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.78 : 1,262.42 = 781.26 : x
  2. Step 2: Convert to fraction form
    842.78/1,262.42 = 781.26/x
  3. Step 3: Cross multiply
    842.78x = 1,262.42 × 781.26
  4. Step 4: Simplify right side
    842.78x = 986,278.25
  5. Step 5: Solve for x
    x = 986,278.25/842.78
  6. Step 6: Final answer
    x = 1,170.27

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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.