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Finding the Fourth Proportional to 768.32, 1,063.20 and 664.64

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Solution

The fourth proportional to 768.32, 1,063.20 and 664.64 is: 919.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    768.32 : 1,063.20 = 664.64 : x
  2. Step 2: Convert to fraction form
    768.32/1,063.20 = 664.64/x
  3. Step 3: Cross multiply
    768.32x = 1,063.20 × 664.64
  4. Step 4: Simplify right side
    768.32x = 706,645.25
  5. Step 5: Solve for x
    x = 706,645.25/768.32
  6. Step 6: Final answer
    x = 919.73

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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.