Home / 1,121.96-1,680.10-938.90

Finding the Fourth Proportional to 1,121.96, 1,680.10 and 938.90

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Solution

The fourth proportional to 1,121.96, 1,680.10 and 938.90 is: 1,405.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.96 : 1,680.10 = 938.90 : x
  2. Step 2: Convert to fraction form
    1,121.96/1,680.10 = 938.90/x
  3. Step 3: Cross multiply
    1,121.96x = 1,680.10 × 938.90
  4. Step 4: Simplify right side
    1,121.96x = 1,577,445.89
  5. Step 5: Solve for x
    x = 1,577,445.89/1,121.96
  6. Step 6: Final answer
    x = 1,405.97

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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.