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Finding the Fourth Proportional to 857.58, 1,286.15 and 309.66

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Solution

The fourth proportional to 857.58, 1,286.15 and 309.66 is: 464.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.58 : 1,286.15 = 309.66 : x
  2. Step 2: Convert to fraction form
    857.58/1,286.15 = 309.66/x
  3. Step 3: Cross multiply
    857.58x = 1,286.15 × 309.66
  4. Step 4: Simplify right side
    857.58x = 398,267.66
  5. Step 5: Solve for x
    x = 398,267.66/857.58
  6. Step 6: Final answer
    x = 464.41

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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.