Home / 1,988.16-2,979.36-1,121.28

Finding the Fourth Proportional to 1,988.16, 2,979.36 and 1,121.28

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Solution

The fourth proportional to 1,988.16, 2,979.36 and 1,121.28 is: 1,680.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,988.16 : 2,979.36 = 1,121.28 : x
  2. Step 2: Convert to fraction form
    1,988.16/2,979.36 = 1,121.28/x
  3. Step 3: Cross multiply
    1,988.16x = 2,979.36 × 1,121.28
  4. Step 4: Simplify right side
    1,988.16x = 3,340,696.78
  5. Step 5: Solve for x
    x = 3,340,696.78/1,988.16
  6. Step 6: Final answer
    x = 1,680.30

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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.