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Finding the Fourth Proportional to 921.62, 1,382.72 and 305.78

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Solution

The fourth proportional to 921.62, 1,382.72 and 305.78 is: 458.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.62 : 1,382.72 = 305.78 : x
  2. Step 2: Convert to fraction form
    921.62/1,382.72 = 305.78/x
  3. Step 3: Cross multiply
    921.62x = 1,382.72 × 305.78
  4. Step 4: Simplify right side
    921.62x = 422,799.68
  5. Step 5: Solve for x
    x = 422,799.68/921.62
  6. Step 6: Final answer
    x = 458.76

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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.