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Finding the Fourth Proportional to 279.80, 385.90 and 206.60

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Solution

The fourth proportional to 279.80, 385.90 and 206.60 is: 284.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.80 : 385.90 = 206.60 : x
  2. Step 2: Convert to fraction form
    279.80/385.90 = 206.60/x
  3. Step 3: Cross multiply
    279.80x = 385.90 × 206.60
  4. Step 4: Simplify right side
    279.80x = 79,726.94
  5. Step 5: Solve for x
    x = 79,726.94/279.80
  6. Step 6: Final answer
    x = 284.94

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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.