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Finding the Fourth Proportional to 640.40, 960.64 and 218.07

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Solution

The fourth proportional to 640.40, 960.64 and 218.07 is: 327.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 960.64 = 218.07 : x
  2. Step 2: Convert to fraction form
    640.40/960.64 = 218.07/x
  3. Step 3: Cross multiply
    640.40x = 960.64 × 218.07
  4. Step 4: Simplify right side
    640.40x = 209,489.82
  5. Step 5: Solve for x
    x = 209,489.82/640.40
  6. Step 6: Final answer
    x = 327.13

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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.