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Finding the Fourth Proportional to 2.57, 3.85 and 2.15

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Solution

The fourth proportional to 2.57, 3.85 and 2.15 is: 3.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.57 : 3.85 = 2.15 : x
  2. Step 2: Convert to fraction form
    2.57/3.85 = 2.15/x
  3. Step 3: Cross multiply
    2.57x = 3.85 × 2.15
  4. Step 4: Simplify right side
    2.57x = 8.27
  5. Step 5: Solve for x
    x = 8.27/2.57
  6. Step 6: Final answer
    x = 3.21

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.