Home / 1,121.27-1,680.39-505.40

Finding the Fourth Proportional to 1,121.27, 1,680.39 and 505.40

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Solution

The fourth proportional to 1,121.27, 1,680.39 and 505.40 is: 757.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.27 : 1,680.39 = 505.40 : x
  2. Step 2: Convert to fraction form
    1,121.27/1,680.39 = 505.40/x
  3. Step 3: Cross multiply
    1,121.27x = 1,680.39 × 505.40
  4. Step 4: Simplify right side
    1,121.27x = 849,260.70
  5. Step 5: Solve for x
    x = 849,260.70/1,121.27
  6. Step 6: Final answer
    x = 757.41

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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.