Statistics Review

1. Which survey question is most likely to result in an unbiased sample?

• Which do you like better, sweet juicy grapes or   boring apples?
• Do you prefer grapes, like I do, or do you   prefer apples?
• Which do you prefer, grapes or apples?
• Don’t you prefer grapes to apples?

2. A total of 360 seventh graders took a math test.  The results of half (180) of the students were chosen at random and listed in the graph.  Which prediction is most likely once all the tests have been scored?

• The second half probably contains the higher   scores, so the graph will change.
• The graph will probably balance out, with all   bars the same height.
• The graph will probably have a shape similar   to the way it appears now.
• The second half probably contains the lower   scores, so the graph will change.

3. Jamal put the names of all students into a bin, and then drew 15.  Which statement is correct?

• This is not a random sample – not every   student has an equal chance to win.
• This is a random sample – every student   has an equal chance to win.  

4. A farmer decides to check the current population of bees in his hive by marking 100 bees.  Later, he collects 240 bees and observes that 42 of them are marked.  What is the best estimate for the bee population?

• 600
• 58
• 74
• 270

5. Jessica took a survey of two sets of 100 classmates to find out their favorite sport and displayed the results in the table below. What can you infer from it?

• More students like track than soccer.
• More students like basketball than soccer.
• Most students like lacrosse.
• More students like soccer than basketball   and track combined.

6. The test scores of five randomly selected students in Ms. Schuch’s 1^st and 3^rd period classes are shown. Which statement is true?

• The 1^st period median is 8 points greater than 3^rd
• The medians in 1^st and 3^rd are the same.
• The 3^rd period median is 7 points greater than 1^st
• The 3^rd period median is 8 points greater than 1^st

7. Test scores were randomly selected from two math classes.  Which statement about the ranges is true?

• The range in 3^rd is 14 points greater than 1^st.
• The range in 1^st is 10 points greater than 3^rd.
• The range in 3^rd is equal to the range in 1^st.
• The range in 1^st is 14 points greater than 3^rd.

8. Test scores were randomly selected from two math classes.  Which statement about the means is true?

• The mean in 1^st is 2 pts. greater than in 3^rd.
• The mean in 3^rd is 6 pts. greater than in 1^st.
• The mean in 1^st is equal to the mean in 3^rd.
• The mean in 3^rd is 24 pts. greater than in 1^st.

9. The table shows the quantity of Jr. Mints and Skittles sold for five days. What is the difference in the medians of the sale numbers for the two candies?

• 13
• 3
• 11
• 5

10. The heights of the starting 5 members of two basketball teams are recorded on the line plots. What conclusion can be drawn about the two teams?

• The heights on team 1 vary more than team 2.
• The heights on team 2 vary more than team 1.
• The two teams have the same range of heights
• The tallest player is on team 2.