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Finding the Fourth Proportional to 419.28, 578.40 and 279.48

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Solution

The fourth proportional to 419.28, 578.40 and 279.48 is: 385.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.28 : 578.40 = 279.48 : x
  2. Step 2: Convert to fraction form
    419.28/578.40 = 279.48/x
  3. Step 3: Cross multiply
    419.28x = 578.40 × 279.48
  4. Step 4: Simplify right side
    419.28x = 161,651.23
  5. Step 5: Solve for x
    x = 161,651.23/419.28
  6. Step 6: Final answer
    x = 385.54

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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.