Answer:
It is not in control because at least two of the of the data points are more than 2 standard deviations from the mean are far apart.
18.3,18.4 > 18.2 Upper Control limit
14.9, > 15.4 Lower Control Limit
Step-by-step explanation:
Find the limits using μ ± 3σ and μ ± 2σ
Using μ ± 3σ
Upper Control Limit = μ + 3σ = 16.8 + 3(0.7)= 16.8 + 2.1= 18.9
Lower Control Limit = μ - 3σ =16.8 - 3(0.7)= 16.8 - 2.1= 14.7
Using μ ± 2σ
Upper Control Limit = μ + 2σ = 16.8 + 2(0.7)= 16.8 + 1.4= 18.2
Lower Control Limit = μ - 2σ =16.8 - 2(0.7)= 16.8 - 1.4= 15.4
The data points are 17.3, 14.9, 18.3, 16.5, 16.1, 17.4, 18.4.
Rearranging these data points 14.9, 16.1, 16.5, 17.3, 17.4, 18.3,18.4.
We see from the above that it is out of control because the values jump above and below the mean.
It is not in control as two of the of the data points are more than 2 standard deviations from the mean are far apart.
