Regression & Predictions

The points in the scatterplot represent paired observations (x, y) where x is an individual’s weight and y is the time (in seconds) it takes for walking on a treadmill to raise the individual’s pulse rate to 140 beats per minute.  The open circles correspond to females and the dark squares to males.

• There is a positive correlation r between gender and weight, since men tend to weigh more than women.
• There is a negative correlation r between weight and time for both males and females.
• In general, males tend to take less time to have their pulse rate raised to 140 bpm while walking on the treadmill.

The scatter plot below shows the number of books read by students in Mrs. Hall’s English class and their final grades. Which statement represents the best description about the line of best fit?

• The more books students read, the lower their English grade.

• The more books students read, the higher their English grade.

• The fewer books students read, the higher their English grade.

• No relationship exists between the number of books students read and their English grades.

What type of association does this graph have?

• positive 
• negative
• none
• all of the above

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

If Joe worked 30 hours, how much is he expected to earn?

• $600
• $200
• $1000
• $800

Tags

CCSS.HSF.IF.A.2

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 weight^=100 + 40(time). Which is the best description of the slope for this regression equation in context of the problem?

• The slope of the line of regression is the time since 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. 

Tags

CCSS.HSF.LE.B.5

Which is the best description of the y - intercept for the linear regression equation of the rats: weight^ = 100 + 40(time)?

• The y-intercept is 100 which means the rat is predicted to weigh 100 grams at birth. 
• The y-intercept is 100, which is where the graph crosses the y-axis. 
• 100 is where the data starts on the y-axis. 

Tags

CCSS.HSF.LE.B.5

Write the linear regression equation for the data set foot length (x) and height (y).

• y = 117.99 + 1.878x
• height^ = 28.39(foot length) + 1.155
• y = 1.878 + 117.99x
• height^ = 117.99 + 1.878(foot length)

Tags

CCSS.HSF.LE.B.5

What is the correlation value?

• .209
• .457
• .13
• .361

Tags

CCSS.HSS.ID.C.8

What kind of trend is shown from this scatter plot?

• positive correlation
• negative correlation
• none
• cannot be determind

The scatter plot shows the relationship between the number of chapters and the total number of pages for several books.  Use the trend line to predict how many chapters would be in a book with 180 pages. 

• 12 chapters
• 15 chapters
• 18 chapters
• 21 chapters

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7