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Finding the Fourth Proportional to 921.54, 1,382.31 and 660

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Solution

The fourth proportional to 921.54, 1,382.31 and 660 is: 990

Step by Step Solution

  1. Step 1: Write the proportion equation
    921.54 : 1,382.31 = 660 : x
  2. Step 2: Convert to fraction form
    921.54/1,382.31 = 660/x
  3. Step 3: Cross multiply
    921.54x = 1,382.31 × 660
  4. Step 4: Simplify right side
    921.54x = 912,324.60
  5. Step 5: Solve for x
    x = 912,324.60/921.54
  6. Step 6: Final answer
    x = 990

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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.