Home / 1,280.75-1,921.40-415.13

Finding the Fourth Proportional to 1,280.75, 1,921.40 and 415.13

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Solution

The fourth proportional to 1,280.75, 1,921.40 and 415.13 is: 622.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.75 : 1,921.40 = 415.13 : x
  2. Step 2: Convert to fraction form
    1,280.75/1,921.40 = 415.13/x
  3. Step 3: Cross multiply
    1,280.75x = 1,921.40 × 415.13
  4. Step 4: Simplify right side
    1,280.75x = 797,630.78
  5. Step 5: Solve for x
    x = 797,630.78/1,280.75
  6. Step 6: Final answer
    x = 622.78

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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.