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Finding the Fourth Proportional to 419.81, 579.60 and 399.35

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Solution

The fourth proportional to 419.81, 579.60 and 399.35 is: 551.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.81 : 579.60 = 399.35 : x
  2. Step 2: Convert to fraction form
    419.81/579.60 = 399.35/x
  3. Step 3: Cross multiply
    419.81x = 579.60 × 399.35
  4. Step 4: Simplify right side
    419.81x = 231,460.36
  5. Step 5: Solve for x
    x = 231,460.36/419.81
  6. Step 6: Final answer
    x = 551.35

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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.