Home / 1,121.23-1,680.72-427.72

Finding the Fourth Proportional to 1,121.23, 1,680.72 and 427.72

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Solution

The fourth proportional to 1,121.23, 1,680.72 and 427.72 is: 641.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.23 : 1,680.72 = 427.72 : x
  2. Step 2: Convert to fraction form
    1,121.23/1,680.72 = 427.72/x
  3. Step 3: Cross multiply
    1,121.23x = 1,680.72 × 427.72
  4. Step 4: Simplify right side
    1,121.23x = 718,877.56
  5. Step 5: Solve for x
    x = 718,877.56/1,121.23
  6. Step 6: Final answer
    x = 641.15

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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.