Home / 1,988.30-2,979.60-1,120.78

Finding the Fourth Proportional to 1,988.30, 2,979.60 and 1,120.78

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Solution

The fourth proportional to 1,988.30, 2,979.60 and 1,120.78 is: 1,679.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,988.30 : 2,979.60 = 1,120.78 : x
  2. Step 2: Convert to fraction form
    1,988.30/2,979.60 = 1,120.78/x
  3. Step 3: Cross multiply
    1,988.30x = 2,979.60 × 1,120.78
  4. Step 4: Simplify right side
    1,988.30x = 3,339,476.09
  5. Step 5: Solve for x
    x = 3,339,476.09/1,988.30
  6. Step 6: Final answer
    x = 1,679.56

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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.