Home / 1,409.90-2,115.10-680.78

Finding the Fourth Proportional to 1,409.90, 2,115.10 and 680.78

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Solution

The fourth proportional to 1,409.90, 2,115.10 and 680.78 is: 1,021.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,409.90 : 2,115.10 = 680.78 : x
  2. Step 2: Convert to fraction form
    1,409.90/2,115.10 = 680.78/x
  3. Step 3: Cross multiply
    1,409.90x = 2,115.10 × 680.78
  4. Step 4: Simplify right side
    1,409.90x = 1,439,917.78
  5. Step 5: Solve for x
    x = 1,439,917.78/1,409.90
  6. Step 6: Final answer
    x = 1,021.29

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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.