MCQOPTIONS

Explore topic-wise MCQs in Statistical Quality Control.

This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Statistical Quality Control knowledge and support exam preparation. Choose a topic below to get started.

1.	The moving average span w at a time I is defined as ____________
A.	\(M_i=\frac{x_i+x_{i-1}+⋯x_{w+1}}{w}\)
B.	\(M_i=\frac{x_i+x_{i-1}+⋯x_{w+1}}{i}\)
C.	\(M_i=\frac{x_i+x_{i-1}+⋯x_{i-w+1}}{w}\)
D.	\(M_i=\frac{x_i+x_{i-1}+⋯x_{i-w+1}}{i}\)
Answer» D. \(M_i=\frac{x_i+x_{i-1}+⋯x_{i-w+1}}{i}\)

2.	The EWMA chart can be used as a basis for a dynamic process-control algorithm.
A.	True
B.	False
Answer» B. False

3.	Which of these can be used as a forecast of where the process mean will be at the next time period?
A.	p-chart
B.	c-chart
C.	EWMA chart
D.	R-chart
Answer» D. R-chart

4.	The Poisson EWMA has considerably better ability to detect assignable causes than Shewhart c-chart.
A.	True
B.	False
Answer» B. False

5.	EWMA recursion is different in the case of the EWMA charts for normal data and EWMA charts for Poisson data.
A.	True
B.	False
Answer» C.

6.	“AL” in the expression of the LCL of EWMA charts for Poisson distribution, is ______
A.	Lower control limit factor
B.	Lower allowance factor
C.	Life Allowance factor
D.	Last Allowance factor
Answer» B. Lower allowance factor

7.	LCL for EWMA chart for Poisson distribution is written as ____________
A.	LCL=\(μ_0-A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1+λ)^{2i}\big\}}\)
B.	LCL=\(μ_0+A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1+λ)^{2i}\big\}}\)
C.	LCL=\(μ_0+A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
D.	LCL=\(μ_0-A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
Answer» E.

8.	What is the upper limit for the EWMA for Poisson data?
A.	UCL=\(μ_0+A_U \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
B.	UCL=\(μ_0-A_U \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
C.	UCL=\(μ_0-A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
D.	UCL=\(μ_0+A_L \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)
Answer» B. UCL=\(μ_0-A_U \sqrt{\frac{λμ_0}{2-λ}\big\{1-(1-λ)^{2i}\big\}}\)

9.	What is the value of EWMV?
A.	\(S_i^2=λ(x_i-z_i)^2- (1+λ) S_{i-1}^2\)
B.	\(S_i^2=λ(x_i-z_i)^2± (1-λ) S_{i-1}^2\)
C.	\(S_i^2=λ(x_i-z_i)^2- (1-λ) S_{i-1}^2\)
D.	\(S_i^2=λ(x_i-z_i)^2+ (1-λ) S_{i-1}^2\)
Answer» E.

10.	EWMV is ____________
A.	Exponentially weighted mean variability
B.	Exponentially weighted moving variance
C.	Exponentially weighted mean variance
D.	Exponentially weighted moving variability
Answer» C. Exponentially weighted mean variance

11.	EWRMS chart is sensitive to _____________
A.	Process mean only
B.	Process standard deviation only
C.	Neither process mean nor standard deviation
D.	Both, process mean and standard deviation
Answer» E.

12.	What is the lower limit of the EWRMS chart?
A.	LCL=\(3σ_0 \sqrt{\frac{χ_{v,1-\frac{α}{2}}^2}{v}}\)
B.	LCL=\(σ_0 \sqrt{\frac{χ_{v,1-\frac{α}{2}}^2}{2v}}\)
C.	LCL=\(σ_0 \sqrt{\frac{χ_{v,1-\frac{α}{2}}^2}{v}}\)
D.	LCL=\(\frac{σ_0}{2} \sqrt{\frac{χ_{v,1-\frac{α}{2}}^2}{v}}\)
Answer» D. LCL=\(\frac{σ_0}{2} \sqrt{\frac{χ_{v,1-\frac{α}{2}}^2}{v}}\)

13.	EWRMS charts have the upper limit of ____________
A.	UCL=\(σ_0 \sqrt{\frac{χ_{v,\frac{α}{2}}^2}{v}}\)
B.	UCL=\(\frac{σ_0}{2} \sqrt{\frac{χ_{v,\frac{α}{2}}^2}{v}}\)
C.	UCL=\(σ_0 \sqrt{\frac{χ_{v,\frac{α}{2}}^2}{2v}}\)
D.	UCL=\(\sqrt{\frac{χ_{v,\frac{α}{2}}^2}{v}}\)
Answer» B. UCL=\(\frac{σ_0}{2} \sqrt{\frac{χ_{v,\frac{α}{2}}^2}{v}}\)

14.	EWRMS chart plots __________ on the control chart.
A.	Exponentially weighted root moving square error
B.	Exponentially weighted root mean square error
C.	Exponentially weighted root mean signal error
D.	Exponentially weighted root moving signal error
Answer» C. Exponentially weighted root mean signal error

15.	“Si2/σ2” has an approximate __________ distribution.
A.	Normal
B.	Lognormal
C.	Exponential
D.	Chi-square
Answer» E.

16.	What is the value of EWMS?
A.	\(S_i^2= λ(x_i-μ)^2-(1-λ) S_{i-1}^2\)
B.	\(S_i^2= λ(x_i-μ)^2-(1+λ) S_{i-1}^2\)
C.	\(S_i^2= λ(x_i-μ)^2+(1-λ) S_{i-1}^2\)
D.	\(S_i^2= λ(x_i-μ)^2+(1+λ) S_{i-1}^2\)
Answer» D. \(S_i^2= λ(x_i-μ)^2+(1+λ) S_{i-1}^2\)

17.	Who were the first people to introduce the EWMA charts to monitor process standard deviation?
A.	McGregor and Harris
B.	Harris and Roberts
C.	Crowder and Roberts
D.	Harris and Roberts
Answer» B. Harris and Roberts

18.	What is the initial S in EWMS stand for?
A.	Severity error
B.	Signal error
C.	Square error
D.	Simple error
Answer» D. Simple error