Home / 1,328.68-1,990.86-1,261.72

Finding the Fourth Proportional to 1,328.68, 1,990.86 and 1,261.72

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Solution

The fourth proportional to 1,328.68, 1,990.86 and 1,261.72 is: 1,890.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,328.68 : 1,990.86 = 1,261.72 : x
  2. Step 2: Convert to fraction form
    1,328.68/1,990.86 = 1,261.72/x
  3. Step 3: Cross multiply
    1,328.68x = 1,990.86 × 1,261.72
  4. Step 4: Simplify right side
    1,328.68x = 2,511,907.88
  5. Step 5: Solve for x
    x = 2,511,907.88/1,328.68
  6. Step 6: Final answer
    x = 1,890.53

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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.