Improve phase test Flashcards
A Belt has studied the salary and experience (in number of years) data and found that the correlation coefficient equals 0.8. How much percent variation in salary can be explained by the variation in experience (in number of years) using linear regression analysis?
.
0.8
b.
0.64
c.
0.2
d.
0.36
0.64
A Belt is analyzing data for multiple linear regression. She observes collinearity between two independent variables. What does it mean?
a.
An independent variable is correlated with the dependent variable.
b.
There is no correlation between the independent variables.
c.
An independent variable is correlated linearly to another independent variable.
d.
Collinearity has no effect on the regression model fitness.
An independent variable is correlated linearly to another independent variable.
A(n) ___________ may not be an example of visual management.
The correct answer is: fire alarm
At a hotel, staff members take different amounts of time to prepare rooms of the same size. In some cases, towels are missing, rooms are not cleaned, or staff forgets to change bed sheets. Which tool can help to improve the situation at the hotel?
a.
Standardized work
b.
Kanban
c.
SIPOC
d.
TPM
a.
Standardized work
During which phase of 5S can a red tag be used?
sorting
For a valid regression model, which of the following is not correct about the residual analysis?
The variance of the errors varies significantly across the fitted values.
For the given expression Y = a + b × exp(c × X), which regression analysis is suitable to estimate the regression coefficients a, b, and c?
Nonlinear regression analysis
If the large increase in an independent variable causes a dependent variable to decrease insignificantly, then _______ correlation is not an option that should be considered.
a positively weak
In a multiple linear regression model, independent variables are generally continuous, but they can be ordinal.
true/false
true
In the following analysis of variance for simple linear regression, p-value is less than the significant level (0.05) for regression. What does it mean? Analysis of Variance Source DF SS MS F P Regression 1 750.63 750.631 144.38 0.000 Error 90 467.90 5.199 Total 91 1218.53
a.
Regression is not significant.
b.
Simple linear regression is not acceptable.
c.
Regression is significant.
d.
The dependent variable has a nonlinear relationship with the independent variable
Regression is significant.
In the given simple linear regression Y = 4 − 2.5X, what is the value of the regression coefficient?
a.
4
b.
2.5
c.
1
d.
-2.5
-2.5
Nonlinear regression analysis shows higher R-squared value as compared with linear regression analysis.
t/f
false
One box contains 24 water bottles of 500 mL each. Four hundred participants are expected for a 2-hour seminar. Each participant will get one water bottle. How many boxes should the organizer arrange for this seminar with a 10% safety margin?
a.
17
b.
18
c.
16
d.
19
19
The following information is the output of a multiple regression analysis.What is not true about this information? Fits and Diagnostics for Unusual ObservationsObs Y Fit Resid Standardized Residual 10 118.00 84.04 33.96 2.53 R 25 140.00 100.18 39.82 3.17 R X
a.
X denotes a point with a large leverage value in the x direction.
b.
Cook’s distance statistics are used to identify unusual observations.
c.
R denotes an extreme standardized residual with absolute values greater than 2 in the y direction.
d.
Unusual observation can never influence any part of a regression analysis.
Unusual observation can never influence any part of a regression analysis.
The prediction interval in a fitted line plot of a simple linear regression represents a range where a new prediction line/slope is expected to fall.
a.
True
b.
False
true
