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Finding the Fourth Proportional to 2.85, 3.90 and 2.60

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Solution

The fourth proportional to 2.85, 3.90 and 2.60 is: 3.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.85 : 3.90 = 2.60 : x
  2. Step 2: Convert to fraction form
    2.85/3.90 = 2.60/x
  3. Step 3: Cross multiply
    2.85x = 3.90 × 2.60
  4. Step 4: Simplify right side
    2.85x = 10.12
  5. Step 5: Solve for x
    x = 10.12/2.85
  6. Step 6: Final answer
    x = 3.55

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.