AP Stat Scatter Plots

Describe the relationship between the variables.

• no correlation
• strong positive correlation
• strong negative correlation
• weak positive correlation

Describe the correlation in the graph shown.

• Strong Negative
• Strong Positive
• Weak Negative
• Weak Positive

Describe the correlation in the graph shown.

• Strong Negative
• Strong Positive
• Weak Negative
• No Correlation

Describe the correlation in the graph shown.

• Strong Negative
• Strong Positive
• Weak Negative
• Weak Positive

Estimate the correlation coefficient.

• r=0
• r=-1
• r=1
• r=2

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

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

• $600
• $200
• $1000
• $800

If Gold's Gym is looking to buy 30 TVs, how much will each one cost?

• 400
• 750
• 1250
• 0

The chart below tracts starting salaries for health care workers since the year 2000. Find the least squares regression equation.

• yhat = 27541.812 + 839.721x

• yhat = -839.721 + 27541.812x

• yhat = 839.721 + 27541.812x

• yhat = -27541.812 + 839.721x

Some data were collected on the weight of a male white 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 rat. It demonstrates the predicted weight of a laboratory rate after so many weeks 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.