Home / 1,213.10-1,819.66-780.56

Finding the Fourth Proportional to 1,213.10, 1,819.66 and 780.56

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Solution

The fourth proportional to 1,213.10, 1,819.66 and 780.56 is: 1,170.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,213.10 : 1,819.66 = 780.56 : x
  2. Step 2: Convert to fraction form
    1,213.10/1,819.66 = 780.56/x
  3. Step 3: Cross multiply
    1,213.10x = 1,819.66 × 780.56
  4. Step 4: Simplify right side
    1,213.10x = 1,420,353.81
  5. Step 5: Solve for x
    x = 1,420,353.81/1,213.10
  6. Step 6: Final answer
    x = 1,170.85

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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.