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Finding the Fourth Proportional to 825.87, 1,238.69 and 312.75

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Solution

The fourth proportional to 825.87, 1,238.69 and 312.75 is: 469.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    825.87 : 1,238.69 = 312.75 : x
  2. Step 2: Convert to fraction form
    825.87/1,238.69 = 312.75/x
  3. Step 3: Cross multiply
    825.87x = 1,238.69 × 312.75
  4. Step 4: Simplify right side
    825.87x = 387,398.73
  5. Step 5: Solve for x
    x = 387,398.73/825.87
  6. Step 6: Final answer
    x = 469.08

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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.