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Finding the Fourth Proportional to 640.26, 960.78 and 423.99

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Solution

The fourth proportional to 640.26, 960.78 and 423.99 is: 636.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.26 : 960.78 = 423.99 : x
  2. Step 2: Convert to fraction form
    640.26/960.78 = 423.99/x
  3. Step 3: Cross multiply
    640.26x = 960.78 × 423.99
  4. Step 4: Simplify right side
    640.26x = 407,361.11
  5. Step 5: Solve for x
    x = 407,361.11/640.26
  6. Step 6: Final answer
    x = 636.24

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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.