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Finding the Fourth Proportional to 620.33, 855.88 and 399.56

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Solution

The fourth proportional to 620.33, 855.88 and 399.56 is: 551.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.33 : 855.88 = 399.56 : x
  2. Step 2: Convert to fraction form
    620.33/855.88 = 399.56/x
  3. Step 3: Cross multiply
    620.33x = 855.88 × 399.56
  4. Step 4: Simplify right side
    620.33x = 341,970.13
  5. Step 5: Solve for x
    x = 341,970.13/620.33
  6. Step 6: Final answer
    x = 551.28

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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.