Home / 1,390.89-2,086.32-1,321.68

Finding the Fourth Proportional to 1,390.89, 2,086.32 and 1,321.68

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Solution

The fourth proportional to 1,390.89, 2,086.32 and 1,321.68 is: 1,982.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.89 : 2,086.32 = 1,321.68 : x
  2. Step 2: Convert to fraction form
    1,390.89/2,086.32 = 1,321.68/x
  3. Step 3: Cross multiply
    1,390.89x = 2,086.32 × 1,321.68
  4. Step 4: Simplify right side
    1,390.89x = 2,757,447.42
  5. Step 5: Solve for x
    x = 2,757,447.42/1,390.89
  6. Step 6: Final answer
    x = 1,982.51

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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.