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WorksheetsCorrelation & Simple Linear Regression
Total questions: 12
Worksheet time: 10mins
Linear regression analysis produces an equation of Y = 7 - 3.2X. This indicates that:
An X value of 0 would would increase Y by 7.
A 1 unit decrease in X results in a 3.2 unit decrease in Y.
A 1 unit increase in X results in a 3.2 unit increase in Y.
A 1 unit increase in X results in a 3.2 unit decrease in Y.
If x is temperature and y is coffee sales, use the following formula to determine the coffee sales on a 34° day.
y = 6443 - 60x
RM 4,403
RM 219,002
RM 6,417
RM 6,443
Write the equation for the linear regression shown.
y=ax+b
y=0.6x+0.1
y=0.72x+r
y=0.1x+0.6
Estimate the correlation coefficient for this scatterplot.
r = 1.2
r = 0.89
r = 0
r = -0.89
For a regression equation y = 24 -0.3x, the coefficient of correlation should be
negative.
True
False
If the least-squares equation is y = 5 + 2x, then an increase of 1 unit in x is associated with an increase of 2 units in y.
True
False
The value of the ‘coefficient of determination’ (r2) ranges from -1 to +1
True
False
If the correlation coefficient is 0.8, the percentage of variation in the response variable explained by the variation in the explanatory variable is
0.80%
80%
0.64%
64%
Simple linear regression requires that the scales of measurement be expressed in either
nominal or ordinal.
ordinal or ratio.
interval or ratio.
nominal or interval.
Some data were collected on the weight of a male while laboratory rat for the first 25 weeks after its birth. The linear regression equation is
y = 100 + 40x
where,
y = weight in gram
x = time in weeks
Which is the best description of the slope for this regression equation?
The slope of the line of regression is the time since the birth of the rate. It demonstrates the predicted weight of a laboratory rate after so many months since birth.
The slope is 40 grams/week which means the mouse gains about 40 grams per week after birth.
The slope is 40 and it means for every increase in weeks the graph will increase.
The slope is 40, which tells us the line increases.
