Home / 1,213.32-1,821.12-780.72

Finding the Fourth Proportional to 1,213.32, 1,821.12 and 780.72

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Solution

The fourth proportional to 1,213.32, 1,821.12 and 780.72 is: 1,171.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,213.32 : 1,821.12 = 780.72 : x
  2. Step 2: Convert to fraction form
    1,213.32/1,821.12 = 780.72/x
  3. Step 3: Cross multiply
    1,213.32x = 1,821.12 × 780.72
  4. Step 4: Simplify right side
    1,213.32x = 1,421,784.81
  5. Step 5: Solve for x
    x = 1,421,784.81/1,213.32
  6. Step 6: Final answer
    x = 1,171.81

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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.