Home / 1,321.20-1,992.42-1,312.56

Finding the Fourth Proportional to 1,321.20, 1,992.42 and 1,312.56

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Solution

The fourth proportional to 1,321.20, 1,992.42 and 1,312.56 is: 1,979.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,321.20 : 1,992.42 = 1,312.56 : x
  2. Step 2: Convert to fraction form
    1,321.20/1,992.42 = 1,312.56/x
  3. Step 3: Cross multiply
    1,321.20x = 1,992.42 × 1,312.56
  4. Step 4: Simplify right side
    1,321.20x = 2,615,170.80
  5. Step 5: Solve for x
    x = 2,615,170.80/1,321.20
  6. Step 6: Final answer
    x = 1,979.39

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.