Home / 1,121.21-1,680.63-427.43

Finding the Fourth Proportional to 1,121.21, 1,680.63 and 427.43

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Solution

The fourth proportional to 1,121.21, 1,680.63 and 427.43 is: 640.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.21 : 1,680.63 = 427.43 : x
  2. Step 2: Convert to fraction form
    1,121.21/1,680.63 = 427.43/x
  3. Step 3: Cross multiply
    1,121.21x = 1,680.63 × 427.43
  4. Step 4: Simplify right side
    1,121.21x = 718,351.68
  5. Step 5: Solve for x
    x = 718,351.68/1,121.21
  6. Step 6: Final answer
    x = 640.69

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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.