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Finding the Fourth Proportional to 660.52, 989.86 and 640.81

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Solution

The fourth proportional to 660.52, 989.86 and 640.81 is: 960.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.52 : 989.86 = 640.81 : x
  2. Step 2: Convert to fraction form
    660.52/989.86 = 640.81/x
  3. Step 3: Cross multiply
    660.52x = 989.86 × 640.81
  4. Step 4: Simplify right side
    660.52x = 634,304.03
  5. Step 5: Solve for x
    x = 634,304.03/660.52
  6. Step 6: Final answer
    x = 960.32

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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.