Home / 3,121.52-4,678.68-1,389.20

Finding the Fourth Proportional to 3,121.52, 4,678.68 and 1,389.20

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Solution

The fourth proportional to 3,121.52, 4,678.68 and 1,389.20 is: 2,082.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,121.52 : 4,678.68 = 1,389.20 : x
  2. Step 2: Convert to fraction form
    3,121.52/4,678.68 = 1,389.20/x
  3. Step 3: Cross multiply
    3,121.52x = 4,678.68 × 1,389.20
  4. Step 4: Simplify right side
    3,121.52x = 6,499,622.26
  5. Step 5: Solve for x
    x = 6,499,622.26/3,121.52
  6. Step 6: Final answer
    x = 2,082.20

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1.5x scale

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.