Home / 1,205.36-1,664.20-780.80

Finding the Fourth Proportional to 1,205.36, 1,664.20 and 780.80

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Solution

The fourth proportional to 1,205.36, 1,664.20 and 780.80 is: 1,078.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,205.36 : 1,664.20 = 780.80 : x
  2. Step 2: Convert to fraction form
    1,205.36/1,664.20 = 780.80/x
  3. Step 3: Cross multiply
    1,205.36x = 1,664.20 × 780.80
  4. Step 4: Simplify right side
    1,205.36x = 1,299,407.36
  5. Step 5: Solve for x
    x = 1,299,407.36/1,205.36
  6. Step 6: Final answer
    x = 1,078.02

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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.