Home / 3,121.81-4,309.35-2,128.09

Finding the Fourth Proportional to 3,121.81, 4,309.35 and 2,128.09

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Solution

The fourth proportional to 3,121.81, 4,309.35 and 2,128.09 is: 2,937.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,121.81 : 4,309.35 = 2,128.09 : x
  2. Step 2: Convert to fraction form
    3,121.81/4,309.35 = 2,128.09/x
  3. Step 3: Cross multiply
    3,121.81x = 4,309.35 × 2,128.09
  4. Step 4: Simplify right side
    3,121.81x = 9,170,685.94
  5. Step 5: Solve for x
    x = 9,170,685.94/3,121.81
  6. Step 6: Final answer
    x = 2,937.62

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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.