A WarmUp (stop At Bold Line) Name A

a. warm-up (stop at bold line): name __________________________________________ a gym has 69 members. 38 of these members are boys. there a

A. Warm-Up (stop at bold line): Name
__________________________________________
A gym has 69 members. 38 of these members are boys. There are 19
members who are girls and under 15 years old. There are 23 members who
are boys 15 and over. Complete the two-way frequency table.
Under 15
15 and Over
Total
Boys
Girls
Total
How many members of the gym are girls 15 years old or over? _________
What percentage of the girls does this represent? Show your
calculation: __________________
What percentage of all members does this represent? Show your
calculation: __________________
What percentage of those who are 15 years or older are girls? Show
your calculation: __________________

Conditional Relative Frequency: The ratio of the value of a joint
relative frequency to the marginal relative frequency expressed as a
decimal. (These are found by using row totals OR column totals.)
B. Think about it: Suppose we want to show the percentage of boys who
are under 15 compared to all boys. In the table above, boys are in the
first row. Make a table that shows relative frequencies by row.
Under 15
15 and Over
Total
Boys
Girls
Total
What is the relative frequency of boys who are under 15 to all boys?
__________________
What is the relative frequency of members who are under 15?
__________________
C. Think about it: Suppose we want to show the percentage of boys who
are under 15 as compared to all members who are under 15. Members
under 15 are shown in the first column. Construct a table that shows
the relative frequencies by column.
Under 15
15 and Over
Total
Boys
Girls
Total
What is the relative frequency of members under 15 who are boys?
__________________
What is the relative frequency of girls to all members?
__________________
D.
Halloween Survey
You randomly survey students in a school about whether they dressed up
for Halloween this year.
Grade 6 Students: 28 dressed up, 10 not dressed up
Grade 7 Students: 19 dressed up, 16 not dressed up
Grade 8 Students: 7 dressed up, 10 not dressed up
a.
Make a two-way table including totals of the rows and columns.
b.
For each grade level, what percent of the students in the survey
dressed up? Did not dress up? Organize the results in a two-way
table. DECIDE: by ROW or by COLUMN?
c. Explain what one of the entries in your table in part b means.
________________________________
_________________________________________________________________________________
d. What grade has the lowest percentage of students dressing up?
______________________________
e. Does the table in part b show a relationship between grade level
and dressing up? Explain your
thinking.
_________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________