Home / 1,121.31-1,549.40-861.57

Finding the Fourth Proportional to 1,121.31, 1,549.40 and 861.57

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Solution

The fourth proportional to 1,121.31, 1,549.40 and 861.57 is: 1,190.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.31 : 1,549.40 = 861.57 : x
  2. Step 2: Convert to fraction form
    1,121.31/1,549.40 = 861.57/x
  3. Step 3: Cross multiply
    1,121.31x = 1,549.40 × 861.57
  4. Step 4: Simplify right side
    1,121.31x = 1,334,912.25
  5. Step 5: Solve for x
    x = 1,334,912.25/1,121.31
  6. Step 6: Final answer
    x = 1,190.49

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.