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Finding the Fourth Proportional to 857.55, 1,285.81 and 309.52

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Solution

The fourth proportional to 857.55, 1,285.81 and 309.52 is: 464.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.55 : 1,285.81 = 309.52 : x
  2. Step 2: Convert to fraction form
    857.55/1,285.81 = 309.52/x
  3. Step 3: Cross multiply
    857.55x = 1,285.81 × 309.52
  4. Step 4: Simplify right side
    857.55x = 397,979.92
  5. Step 5: Solve for x
    x = 397,979.92/857.55
  6. Step 6: Final answer
    x = 464.09

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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.