Question

The edge roughness of slit paper products increases as knife blades wear. Only 2% of products slit with new blades have rough edges, 3% of products slit with blades of average sharpness exhibit roughness, and 4% of products slit with worn blades exhibit roughness. If 25% of the blades in the manufacturing are new, 60% are of average sharpness, and 15% are worn, what is the proportion of products that exhibit edge roughness

Answer 1

The proportion of products that exhibit edge roughness is 0.029 = 2.9%.

Explanation:

Proportion of products that exhibit edge roughness:

2% of 25%(new blades).

3% of 60%(average sharpness).

4% of 15%(worn). So

`p = 0.02*0.25 + 0.03*0.6 + 0.04*0.15 = 0.029`

The proportion of products that exhibit edge roughness is 0.029 = 2.9%.