In: Statistics and Probability
Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity paint.
0.83 | 0.87 | 0.89 | 1.02 | 1.09 | 1.14 | 1.27 | 1.29 |
1.46 | 1.51 | 1.60 | 1.64 | 1.67 | 1.70 | 1.78 | 1.83 |
Determine the z percentile associated with each sample observation. (Round your answers to two decimal places.)
Sample observation | 0.83 | 0.87 | 0.89 | 1.02 | 1.09 | 1.14 | 1.27 | 1.29 |
z percentile | ||||||||
Sample observation | 1.46 | 1.51 | 1.60 | 1.64 | 1.67 | 1.70 | 1.78 | 1.83 |
z percentile |
Answer:
Given that,
Construct a normal probability plot for the following sample of observations on coating thickness for low-viscosity paint.
0.83 | 0.87 | 0.89 | 1.02 | 1.09 | 1.14 | 1.27 | 1.29 |
1.46 | 1.51 | 1.60 | 1.64 | 1.67 | 1.70 | 1.78 |
1.83 |
Count: N=16
Sum, Σx=21.59
Mean ():
=Σx/N
=21.59/16
=1.349375
Therefore, the mean=1.3494.
Standard Deviation ():
=Σ(xi - μ)2/N
=1.76749375/16
=√0.110468359375
=0.332367
Therefore, the standard deviation ()=0.3324
Determine the z percentile associated with each sample observation:
Then,
Z-value:
Z-percentile:
By using Z-percentile calculator or Using excel Norm.Inv(T, 0, 1).
Calculation table:
Sample Observation | 0.83 | 0.87 | 0.89 | 1.02 | 1.09 | 1.14 | 1.27 | 1.29 | |
Z-Value | -1.56 | -1.44 | -1.38 | -0.99 | -0.78 | -0.62 | -0.24 | -0.18 | |
Z-Percentile | 5.94 | 7.49 | 8.38 | 16.11 | 21.77 | 26.76 | 40.52 | 42.86 | Mean=1.3494. |
Sample Observation | 1.46 | 1.51 | 1.60 | 1.64 | 1.67 | 1.70 | 1.78 | 1.83 |
Standard deviation () =0.3324 |
Z-Value | 0.33 | 0.48 | 0.75 | 0.87 | 0.97 | 1.06 | 1.29 | 1.45 | |
Z-Percentile | 62.93 | 68.44 | 77.34 | 80.78 | 83.4 | 85.54 | 90.15 | 92.65 |