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Finding the Fourth Proportional to 2.09, 2.85 and 2.05

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Solution

The fourth proportional to 2.09, 2.85 and 2.05 is: 2.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.09 : 2.85 = 2.05 : x
  2. Step 2: Convert to fraction form
    2.09/2.85 = 2.05/x
  3. Step 3: Cross multiply
    2.09x = 2.85 × 2.05
  4. Step 4: Simplify right side
    2.09x = 5.84
  5. Step 5: Solve for x
    x = 5.84/2.09
  6. Step 6: Final answer
    x = 2.80

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.