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Finding the Fourth Proportional to 857.75, 1,286.88 and 492.80

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Solution

The fourth proportional to 857.75, 1,286.88 and 492.80 is: 739.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.75 : 1,286.88 = 492.80 : x
  2. Step 2: Convert to fraction form
    857.75/1,286.88 = 492.80/x
  3. Step 3: Cross multiply
    857.75x = 1,286.88 × 492.80
  4. Step 4: Simplify right side
    857.75x = 634,172
  5. Step 5: Solve for x
    x = 634,172/857.75
  6. Step 6: Final answer
    x = 739.34

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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.