Home / 1,421.20-2,131.72-447.28

Finding the Fourth Proportional to 1,421.20, 2,131.72 and 447.28

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Solution

The fourth proportional to 1,421.20, 2,131.72 and 447.28 is: 670.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,421.20 : 2,131.72 = 447.28 : x
  2. Step 2: Convert to fraction form
    1,421.20/2,131.72 = 447.28/x
  3. Step 3: Cross multiply
    1,421.20x = 2,131.72 × 447.28
  4. Step 4: Simplify right side
    1,421.20x = 953,475.72
  5. Step 5: Solve for x
    x = 953,475.72/1,421.20
  6. Step 6: Final answer
    x = 670.89

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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.