Exercise 19 Understanding Pearson Chi-Square
1. According to the relevant study results section of the Darling-Fisher et al. (2014) study,
what categories are reported to be statistically significant? The statistically significant
differences were noted between RAAPS users and nonusers with respect to
provider types, practice setting, percent of adolescent patients, years in practice,
and practice region.
2. What level of measurement is appropriate for calculating the χ2 statistic?
Give two examples from Table 2 of demographic variables measured at the level
appropriate for χ2.
The level of measurement that is appropriate for calculating the x2
statistic is at the nominal level comparing the frequencies observed compared to
the frequencies expected.
Example 1: provider type: x2=(2, n=161)= 12.7652; p<.00
Example 2: provider age in years: x2 = (2, n=145)= 4.0; p<.14
3. What is the χ2 for U.S. practice region? Is the χ2 value statistically significant? Provide
a rationale for your answer.
X2= 29.68
p= <.00 is statistically significant because it is less than alpha level of
0.05.
, 4. What is the df for provider type? Provide a rationale for why the df for provider type
presented in Table 2 is correct.
df = 2.
The df formula,
df=(R – 1) (C – 1)
There are three “R” rows (health, mental, other). There are two “c” columns,
RAAPS users and RAAPS nonusers.
df=(3 – 1) (2 – 1) = (2) (1) = 2
5.Is there a statistically significant difference for practice setting between the Rapid
Assessment for Adolescent Preventive Services (RAAPS) users and nonusers? Provide a
rationale for your answer.
Yes, there is a statistically significant difference for practice settings between the
RAAPs users and non-users. The Chi square value=12.7652
with p=.00 which is less than the alpha of 0.05 making it statistically
significant.
1. According to the relevant study results section of the Darling-Fisher et al. (2014) study,
what categories are reported to be statistically significant? The statistically significant
differences were noted between RAAPS users and nonusers with respect to
provider types, practice setting, percent of adolescent patients, years in practice,
and practice region.
2. What level of measurement is appropriate for calculating the χ2 statistic?
Give two examples from Table 2 of demographic variables measured at the level
appropriate for χ2.
The level of measurement that is appropriate for calculating the x2
statistic is at the nominal level comparing the frequencies observed compared to
the frequencies expected.
Example 1: provider type: x2=(2, n=161)= 12.7652; p<.00
Example 2: provider age in years: x2 = (2, n=145)= 4.0; p<.14
3. What is the χ2 for U.S. practice region? Is the χ2 value statistically significant? Provide
a rationale for your answer.
X2= 29.68
p= <.00 is statistically significant because it is less than alpha level of
0.05.
, 4. What is the df for provider type? Provide a rationale for why the df for provider type
presented in Table 2 is correct.
df = 2.
The df formula,
df=(R – 1) (C – 1)
There are three “R” rows (health, mental, other). There are two “c” columns,
RAAPS users and RAAPS nonusers.
df=(3 – 1) (2 – 1) = (2) (1) = 2
5.Is there a statistically significant difference for practice setting between the Rapid
Assessment for Adolescent Preventive Services (RAAPS) users and nonusers? Provide a
rationale for your answer.
Yes, there is a statistically significant difference for practice settings between the
RAAPs users and non-users. The Chi square value=12.7652
with p=.00 which is less than the alpha of 0.05 making it statistically
significant.
