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Finding the Fourth Proportional to 921.39, 1,382.18 and 305.12

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Solution

The fourth proportional to 921.39, 1,382.18 and 305.12 is: 457.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.39 : 1,382.18 = 305.12 : x
  2. Step 2: Convert to fraction form
    921.39/1,382.18 = 305.12/x
  3. Step 3: Cross multiply
    921.39x = 1,382.18 × 305.12
  4. Step 4: Simplify right side
    921.39x = 421,730.76
  5. Step 5: Solve for x
    x = 421,730.76/921.39
  6. Step 6: Final answer
    x = 457.71

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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.