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Finding the Fourth Proportional to 619.83, 855.54 and 399.38

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Solution

The fourth proportional to 619.83, 855.54 and 399.38 is: 551.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.83 : 855.54 = 399.38 : x
  2. Step 2: Convert to fraction form
    619.83/855.54 = 399.38/x
  3. Step 3: Cross multiply
    619.83x = 855.54 × 399.38
  4. Step 4: Simplify right side
    619.83x = 341,681.29
  5. Step 5: Solve for x
    x = 341,681.29/619.83
  6. Step 6: Final answer
    x = 551.25

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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.