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Finding the Fourth Proportional to 640.05, 883.34 and 391.32

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Solution

The fourth proportional to 640.05, 883.34 and 391.32 is: 540.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.05 : 883.34 = 391.32 : x
  2. Step 2: Convert to fraction form
    640.05/883.34 = 391.32/x
  3. Step 3: Cross multiply
    640.05x = 883.34 × 391.32
  4. Step 4: Simplify right side
    640.05x = 345,666.65
  5. Step 5: Solve for x
    x = 345,666.65/640.05
  6. Step 6: Final answer
    x = 540.06

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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.