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Finding the Fourth Proportional to 857.88, 1,286.18 and 771

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Solution

The fourth proportional to 857.88, 1,286.18 and 771 is: 1,155.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.88 : 1,286.18 = 771 : x
  2. Step 2: Convert to fraction form
    857.88/1,286.18 = 771/x
  3. Step 3: Cross multiply
    857.88x = 1,286.18 × 771
  4. Step 4: Simplify right side
    857.88x = 991,644.78
  5. Step 5: Solve for x
    x = 991,644.78/857.88
  6. Step 6: Final answer
    x = 1,155.92

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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.