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Finding the Fourth Proportional to 2.65, 3.98 and 1.31

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Solution

The fourth proportional to 2.65, 3.98 and 1.31 is: 1.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.65 : 3.98 = 1.31 : x
  2. Step 2: Convert to fraction form
    2.65/3.98 = 1.31/x
  3. Step 3: Cross multiply
    2.65x = 3.98 × 1.31
  4. Step 4: Simplify right side
    2.65x = 5.22
  5. Step 5: Solve for x
    x = 5.22/2.65
  6. Step 6: Final answer
    x = 1.97

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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.