Home / 3,121.70-4,308.09-2,128.10

Finding the Fourth Proportional to 3,121.70, 4,308.09 and 2,128.10

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Solution

The fourth proportional to 3,121.70, 4,308.09 and 2,128.10 is: 2,936.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,121.70 : 4,308.09 = 2,128.10 : x
  2. Step 2: Convert to fraction form
    3,121.70/4,308.09 = 2,128.10/x
  3. Step 3: Cross multiply
    3,121.70x = 4,308.09 × 2,128.10
  4. Step 4: Simplify right side
    3,121.70x = 9,168,046.33
  5. Step 5: Solve for x
    x = 9,168,046.33/3,121.70
  6. Step 6: Final answer
    x = 2,936.88

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.