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Finding the Fourth Proportional to 640.40, 883.13 and 388.26

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Solution

The fourth proportional to 640.40, 883.13 and 388.26 is: 535.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.40 : 883.13 = 388.26 : x
  2. Step 2: Convert to fraction form
    640.40/883.13 = 388.26/x
  3. Step 3: Cross multiply
    640.40x = 883.13 × 388.26
  4. Step 4: Simplify right side
    640.40x = 342,882.11
  5. Step 5: Solve for x
    x = 342,882.11/640.40
  6. Step 6: Final answer
    x = 535.42

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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.