PSTAT midterm EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS VERIFIED
parameter a numerical characteristic of a population
statistic a numerical characteristic of a sample
quantitative variable takes numerical values for which it makes
sense to find an average
categorical variable a variable that names categories
(whether with words or numerals)
symmetric distribution uses the mean and SD for center and
spread, affected by outliers
skwed distrubution uses the median and IQR for center and
spread, mean follows tail, resistant to
outliers
skewed left mean < median, ski left
skewed right mean > median
, population A group of were interested in studying
experiment the rearscher determines participant
groups, used to see causation, random
assignment
observational study reaershcer doesnt make changes or assign
groups
random sampling Samples naturally vary, likely
representative ofthe population, avoiding
bias, meaning we can generalize to the
whole population, GENERALIZE
random assignemnt How participants get assigned to treatment
groups in experiments, used for
causation, CAUSATION
WITH COMPLETE SOLUTIONS VERIFIED
parameter a numerical characteristic of a population
statistic a numerical characteristic of a sample
quantitative variable takes numerical values for which it makes
sense to find an average
categorical variable a variable that names categories
(whether with words or numerals)
symmetric distribution uses the mean and SD for center and
spread, affected by outliers
skwed distrubution uses the median and IQR for center and
spread, mean follows tail, resistant to
outliers
skewed left mean < median, ski left
skewed right mean > median
, population A group of were interested in studying
experiment the rearscher determines participant
groups, used to see causation, random
assignment
observational study reaershcer doesnt make changes or assign
groups
random sampling Samples naturally vary, likely
representative ofthe population, avoiding
bias, meaning we can generalize to the
whole population, GENERALIZE
random assignemnt How participants get assigned to treatment
groups in experiments, used for
causation, CAUSATION
