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Finding the Fourth Proportional to 2.61, 3.91 and 2.16

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Solution

The fourth proportional to 2.61, 3.91 and 2.16 is: 3.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.61 : 3.91 = 2.16 : x
  2. Step 2: Convert to fraction form
    2.61/3.91 = 2.16/x
  3. Step 3: Cross multiply
    2.61x = 3.91 × 2.16
  4. Step 4: Simplify right side
    2.61x = 8.45
  5. Step 5: Solve for x
    x = 8.45/2.61
  6. Step 6: Final answer
    x = 3.24

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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.