STT 231 EXAM 3 COMPLETE QUESTIONS
WITH VERIFIED ANSWERS
\.A study was conducted to identify the factors affecting quality of sleep for
university students. A survey of 290 students of different majors aged 17-29 years
old revealed that 67.2% of these students suffered from poor sleep.Further
analyses were conducted based off the original study of 290 university students in
the question above. A second study assessed if the distribution of sleep quality
was the same for the various age groups of Young (19 years old or younger),
Middle (over19 but less than 24 years old), and Old (24 years and older) university
students. The following data shows the sleep quality results for each group.a.
Select the name of the test that should be used to assess if the distribution of the
responses is the same for the three age-group populations
𝜒 ^2 test of independence or 𝜒^2 goodness of fit test - ANSWERS✔-𝜒^2 test of
independence
\.chi squared test of independence - ANSWERS✔-A statistical test in which both
variables are categorical. This test generally tells us if the distribution of
participants across categories is different from what would happen if there were
no difference between the groups
\.Squared test statistic has two consequences - ANSWERS✔-1. all x^2 statistics are
positive
2. cells that are already unusual are further emphasized (side effect)
, \.Chi-square distributions are skewed to the ______ and take on only _______
values. - ANSWERS✔-Right, positive
\.What is standard deviation in chi-squared? - ANSWERS✔-sqrt(2df)
\.chi squared goodness of fit - ANSWERS✔-A hypothesis test that assesses
whether the distribution of a single categorical variable follows a proposed
distribution.
Using the 𝜒 2 statistic, it compares the observed counts with the counts we would
expect to see if the observed data perfectly obeyed the proposed distribution.
USES A SINGLE CATEGORICAL VARIABLE.
\.degrees of freedom - ANSWERS✔-k-1 k being categories
\.Computing expected counts for a two-way table (Cross-product rule) -
ANSWERS✔-expected value = (column total)(row total) / overall total
\.If the distribution of the sleep quality is the same for the three age populations
of university students, what is the expected value of the test statistic? -
ANSWERS✔-2
WITH VERIFIED ANSWERS
\.A study was conducted to identify the factors affecting quality of sleep for
university students. A survey of 290 students of different majors aged 17-29 years
old revealed that 67.2% of these students suffered from poor sleep.Further
analyses were conducted based off the original study of 290 university students in
the question above. A second study assessed if the distribution of sleep quality
was the same for the various age groups of Young (19 years old or younger),
Middle (over19 but less than 24 years old), and Old (24 years and older) university
students. The following data shows the sleep quality results for each group.a.
Select the name of the test that should be used to assess if the distribution of the
responses is the same for the three age-group populations
𝜒 ^2 test of independence or 𝜒^2 goodness of fit test - ANSWERS✔-𝜒^2 test of
independence
\.chi squared test of independence - ANSWERS✔-A statistical test in which both
variables are categorical. This test generally tells us if the distribution of
participants across categories is different from what would happen if there were
no difference between the groups
\.Squared test statistic has two consequences - ANSWERS✔-1. all x^2 statistics are
positive
2. cells that are already unusual are further emphasized (side effect)
, \.Chi-square distributions are skewed to the ______ and take on only _______
values. - ANSWERS✔-Right, positive
\.What is standard deviation in chi-squared? - ANSWERS✔-sqrt(2df)
\.chi squared goodness of fit - ANSWERS✔-A hypothesis test that assesses
whether the distribution of a single categorical variable follows a proposed
distribution.
Using the 𝜒 2 statistic, it compares the observed counts with the counts we would
expect to see if the observed data perfectly obeyed the proposed distribution.
USES A SINGLE CATEGORICAL VARIABLE.
\.degrees of freedom - ANSWERS✔-k-1 k being categories
\.Computing expected counts for a two-way table (Cross-product rule) -
ANSWERS✔-expected value = (column total)(row total) / overall total
\.If the distribution of the sleep quality is the same for the three age populations
of university students, what is the expected value of the test statistic? -
ANSWERS✔-2
