Home / 1,280.80-1,921.50-415.11

Finding the Fourth Proportional to 1,280.80, 1,921.50 and 415.11

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Solution

The fourth proportional to 1,280.80, 1,921.50 and 415.11 is: 622.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.80 : 1,921.50 = 415.11 : x
  2. Step 2: Convert to fraction form
    1,280.80/1,921.50 = 415.11/x
  3. Step 3: Cross multiply
    1,280.80x = 1,921.50 × 415.11
  4. Step 4: Simplify right side
    1,280.80x = 797,633.87
  5. Step 5: Solve for x
    x = 797,633.87/1,280.80
  6. Step 6: Final answer
    x = 622.76

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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.