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Finding the Fourth Proportional to 418.90, 578.10 and 278.80

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Solution

The fourth proportional to 418.90, 578.10 and 278.80 is: 384.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.90 : 578.10 = 278.80 : x
  2. Step 2: Convert to fraction form
    418.90/578.10 = 278.80/x
  3. Step 3: Cross multiply
    418.90x = 578.10 × 278.80
  4. Step 4: Simplify right side
    418.90x = 161,172.09
  5. Step 5: Solve for x
    x = 161,172.09/418.90
  6. Step 6: Final answer
    x = 384.75

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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.