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Finding the Fourth Proportional to 857.48, 1,286.18 and 309.70

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Solution

The fourth proportional to 857.48, 1,286.18 and 309.70 is: 464.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.48 : 1,286.18 = 309.70 : x
  2. Step 2: Convert to fraction form
    857.48/1,286.18 = 309.70/x
  3. Step 3: Cross multiply
    857.48x = 1,286.18 × 309.70
  4. Step 4: Simplify right side
    857.48x = 398,329.95
  5. Step 5: Solve for x
    x = 398,329.95/857.48
  6. Step 6: Final answer
    x = 464.54

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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.