Home / 1,243.38-1,865.51-780.61

Finding the Fourth Proportional to 1,243.38, 1,865.51 and 780.61

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Solution

The fourth proportional to 1,243.38, 1,865.51 and 780.61 is: 1,171.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,243.38 : 1,865.51 = 780.61 : x
  2. Step 2: Convert to fraction form
    1,243.38/1,865.51 = 780.61/x
  3. Step 3: Cross multiply
    1,243.38x = 1,865.51 × 780.61
  4. Step 4: Simplify right side
    1,243.38x = 1,456,235.76
  5. Step 5: Solve for x
    x = 1,456,235.76/1,243.38
  6. Step 6: Final answer
    x = 1,171.19

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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.