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Finding the Fourth Proportional to 640.19, 883.35 and 391.58

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Solution

The fourth proportional to 640.19, 883.35 and 391.58 is: 540.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.19 : 883.35 = 391.58 : x
  2. Step 2: Convert to fraction form
    640.19/883.35 = 391.58/x
  3. Step 3: Cross multiply
    640.19x = 883.35 × 391.58
  4. Step 4: Simplify right side
    640.19x = 345,902.19
  5. Step 5: Solve for x
    x = 345,902.19/640.19
  6. Step 6: Final answer
    x = 540.31

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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.