NEW
Font size
WorksheetsIntro to Stat Linear Regression review
Total questions: 48
Worksheet time: 2hrs 9mins
Use the data to calculate the prediction line and use the equation to predict the number of prom tickets sold on day 6.
y(hat) = 4.54 + 27.31x ; prom tickets are estimated to be about 58.93
y(hat) = 27.31 + 4.54x ; prom tickets are estimated to be about 54.55
y(hat) = .97 + 4.54x ; prom tickets are expected to be about 41.24
r2 = 0.83 means
My data is very accurate. We have a 17% uncertainty.
My data is 17% correct.
83% of the variability in y can be explained by x. Only 17% is unexplained.
My data is very accurate. I have 17% accuracy.
The coefficient of determination is a percentage "r2" such that:
0 ≤ r2 ≤ 1
-1 < r2 < 1
0 < r2 < 2
-1 < r2 <0
r2 = 0.24 means
76% of the variability in y is unexplained. This is not good.
My data is 24% correct.
My data is flawed. I have 24% uncertainty.
My data is very accurate. I have 76% accuracy.
r = 0.99999 mean?
The outside temperature and the amount of layers you wear.
y= 40x+100, where x is number of weeks and y is weight in grams.
What does the y-intercept mean in context of the problem?
A restaurant sells pizza for the prices in the data table. Calculate the linear regression equation of the data.
y = 12 + 1.5x
y = 12x + 1.5
y = 0.67x - 8
y = -8x + 0.67
Estimate the correlation coefficient for this scatterplot.
r = 1.2
r = 0.89
r = 0
r = -0.89
The residual plots from five different least squares regression lines are shown below. Which of the plots shows the strongest evidence that its regression line is an appropriate model for the data and is consistent with the assumptions required for inference for regression?
The equation of the least squares regression line for a set of data is y=0.68+1.21x. What is the residual for the point (3, 4)?
-0.31
-0.68
-1.52
-3.63
-4.31
What is the slope of this prediction equation?
1344
19
-19
-19x
What is the y-intercept of the prediction equation?
-149
149
4.4
4.4x
predicted math grade = 65 + 2.56(study hours)
What does the slope mean in context?
The model predicts an increase of 2.56 points in the math grade per hour studied, on average.
The model predicts an increase of 65 points in the math grade per hour studied, on average.
The model predicts an increase of 2.56 study hours per math grade, on average.
The model predicts an increase of 2.56 study hours, on average.
predicted cost = 3 + 4.1(length of movie in hours)
According to this prediction model, how much do you expect to pay for a movie if the movie is 1.5 hours long?
$3
$7.10
$9.15
$4.10
which value of x has the greatest residual?
5
2
1
3
The scatter plot shows the number coffee shops in different cities and the number of violent crimes. Which of the following is NOT true?
A) As the number of coffee shops increase, violent crimes appears to increase.
B) The line of best fit (regression line) shows a positive correlation
C) The data has a positive correlation coefficient
D) An increase in coffee shops causes an increase in violent crimes
The results of a linear regression are shown.
Which phrase best describes the relationship between x and y?
strong negative correlation
strong positive correlation
weak negative correlation
weak positive correlation
Which graph most clearly shows a negative correlation between the x- and y−values?
Which graph most clearly shows a no correlation between the x- and y−values?
What does a correlation coefficient of r=−0.01
imply about the graph of a data set? Select all that apply.
A linear model is not a good fit for the data.
A linear model is a good fit for the data.
Which correlation coefficient is most accurate for this data set?
r = - 0.3
r = 0.99
r = -0.99
The linear regression equation that best represents the line of best fit for the data is y=20.8x-35. What does the slope represent?
The number of bacteria increase by 20.8 per hour
The number of bacteria increase by 20.8 per minute
The number of bacteria decrease by 35 per hour
The number of bacteria decrease by 35 per minute
The linear regression equation that best represents the line of best fit for the data is y= -35 + 20.8x. Use the equation to predict the number of bacteria in 24 hours.
35
277
464
819
A person travels by car. They record their miles driven in a data table. Calculate the linear regression equation of this data.
y = - 1.79 + 61.93x
y = 61.93 - 1.79x
y = 0.016x + 0.03
y = 0.0160 - .03x
