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Finding the Fourth Proportional to 620.04, 855.36 and 399.18

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Solution

The fourth proportional to 620.04, 855.36 and 399.18 is: 550.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.04 : 855.36 = 399.18 : x
  2. Step 2: Convert to fraction form
    620.04/855.36 = 399.18/x
  3. Step 3: Cross multiply
    620.04x = 855.36 × 399.18
  4. Step 4: Simplify right side
    620.04x = 341,442.60
  5. Step 5: Solve for x
    x = 341,442.60/620.04
  6. Step 6: Final answer
    x = 550.68

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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.