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Finding the Fourth Proportional to 2.89, 4.31 and 2.80

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Solution

The fourth proportional to 2.89, 4.31 and 2.80 is: 4.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.89 : 4.31 = 2.80 : x
  2. Step 2: Convert to fraction form
    2.89/4.31 = 2.80/x
  3. Step 3: Cross multiply
    2.89x = 4.31 × 2.80
  4. Step 4: Simplify right side
    2.89x = 12.07
  5. Step 5: Solve for x
    x = 12.07/2.89
  6. Step 6: Final answer
    x = 4.18

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.