AP Statistics Quiz 11.2
Name:
DegukB
1. Determine which chi-square test is appropriate in each of the following settings. Explain your reasoning. Do
not carry out the test!
(a) Have older cell-phone users caught on to texting? A random sample of individuals who are less than 30
years old and a random sample of individuals who are at least 30 years old were asked if they make
more phone calls or send more text messages on their cell phone on a typical day. Here are the results:
Response to
question
More texts
More phone calls
Total
I categorical
Age group
Less than 30 At least 30
146
32
34
98
180
130
Total
178
132
310
2 populations Conduct a thi
Squaretestof
A
Homogeneity
response to
question
(b) Are older and younger employees equally prone to having accidents? To investigate this question, a
researcher at a light manufacturing plant classified a random sample of accidents by type and by age of
the employee.
Accident type
Sprain Burn Cut Total
Less than 25
9
17
5
31
Age
At least 25
61
13
12
86
Total
70
30
17
117
Accifttyre age
2 categoricalvariables from1 population so use
Chisquare testof independence
Starnes/Tabor, The Practice of Statistics, 6/e
I
accidents
© 2018 BFW Publishers, Inc.
2. Mrs. Overstreet is studying fathers' involvement in their children's education. She interviews a random
sample of fathers of school-age children in a large school district. One question concerns regularly
scheduled parent-teacher conferences. Here is a two-way table of the results:
Expectedtakes
10334 112.53 228 12
884 9 63 1952 Two-parent
84 50.30
22.8
24
Family type
Attended all
109
15
11
135
Single-parent
Non-resident father
Total
Attendance rate
Attended some Attended none
132
203
10
13
5
82
147
298
Total
444
38
98
580
(a) The segmented bar graph (provided below) illustrates the relationship between these two variables.
Describe what you see.
It seems that the singh family
fathers attend conferences morecomp
to
on tho types th non resident
fathers seem to
not gotochild
conferences
(b) Do the data give convincing statistical evidence of an association between family type and how often
fathers attended parent-teacher conferences?
chi gofindep
theschool
is no associationbetweenAttendancerateandfamilytype in
State Ho there
distribution
school
the
Tee
is an associationbetweenAttendancerateandfamilytype in
distribution
RandomStatedthatthis is a
Ian
random
101 580 islessthan101
largecounts All
sample
of allfathers
expectedcounts
so x
limit
one since
th pale
galto5
aregreaterore
43115,1 t
1
18258
is
42 54.774
O werejectthenullandMarly
infavor
ofalternatewith association between
Starnes/Tabor, The Practice of Statistics, 6/e
p
attending
value to
and familytype
54.724
d7 4
© 2018 BFW Publishers, Inc.
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