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Finding the Fourth Proportional to 399.74, 551.36 and 355.39

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Solution

The fourth proportional to 399.74, 551.36 and 355.39 is: 490.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.74 : 551.36 = 355.39 : x
  2. Step 2: Convert to fraction form
    399.74/551.36 = 355.39/x
  3. Step 3: Cross multiply
    399.74x = 551.36 × 355.39
  4. Step 4: Simplify right side
    399.74x = 195,945.34
  5. Step 5: Solve for x
    x = 195,945.34/399.74
  6. Step 6: Final answer
    x = 490.19

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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.