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Finding the Fourth Proportional to 1,009, 1,392.57 and 660.43

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Solution

The fourth proportional to 1,009, 1,392.57 and 660.43 is: 911.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,009 : 1,392.57 = 660.43 : x
  2. Step 2: Convert to fraction form
    1,009/1,392.57 = 660.43/x
  3. Step 3: Cross multiply
    1,009x = 1,392.57 × 660.43
  4. Step 4: Simplify right side
    1,009x = 919,695.01
  5. Step 5: Solve for x
    x = 919,695.01/1,009
  6. Step 6: Final answer
    x = 911.49

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.