Home / 1,421.24-2,131.85-381.21

Finding the Fourth Proportional to 1,421.24, 2,131.85 and 381.21

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Solution

The fourth proportional to 1,421.24, 2,131.85 and 381.21 is: 571.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.24 : 2,131.85 = 381.21 : x
  2. Step 2: Convert to fraction form
    1,421.24/2,131.85 = 381.21/x
  3. Step 3: Cross multiply
    1,421.24x = 2,131.85 × 381.21
  4. Step 4: Simplify right side
    1,421.24x = 812,680.63
  5. Step 5: Solve for x
    x = 812,680.63/1,421.24
  6. Step 6: Final answer
    x = 571.81

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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.