EDPSY 490 final study guide Question
and answers verified to pass
2025/2026
parsimony - correct answer ✔capturing the essence of the data in the simplest manner possible,
without misrepresenting the data
population - correct answer ✔the scores we wish to know about (aka "truth")
parameters - correct answer ✔numerical descriptions (quantities) of a population (of scores) -> "truth"
statistics - correct answer ✔numerical descriptions (quantities) of a sample of scores -> "reality"
µ formal definition - correct answer ✔E(X)
µ computational definition - correct answer ✔summation of (x)/n
σ² computational definition - correct answer ✔summation of (x-mu)^2/n
σ² formal definition - correct answer ✔E(x-mu)^2
nominal - correct answer ✔unordered categories
ordinal - correct answer ✔ordered categories
interval - correct answer ✔ordered categories + equal spaces
, ratio - correct answer ✔ordered categories + equal spaces + true zero
formula for a z-score - correct answer ✔(x-mu)/sd
definition of a z-score - correct answer ✔converting an X from its original units to the number of
standard deviations it is from the mean
formula for a 1-group z-test statistic - correct answer ✔(xbar-mu)/true standard error of the means
formula for a 2-group t-test statistic - correct answer ✔(xbar1 - xbar2) - (mu1 - mu2)/standard error of
the mean differences
unbiasedness - correct answer ✔statistic doesn't under/overestimate the parameter
consistency - correct answer ✔as sample size increases, distribution becomes more compact
efficiency - correct answer ✔going for the parameter that has the least variability (mean)
Central Limit Theorem - correct answer ✔tells us the shape of most sampling distributions (we can
assume it is normal if there is a large enough sample size)
z = 1 - correct answer ✔34.13%
z = 2 - correct answer ✔47.72%
z = 3 - correct answer ✔49.87%
and answers verified to pass
2025/2026
parsimony - correct answer ✔capturing the essence of the data in the simplest manner possible,
without misrepresenting the data
population - correct answer ✔the scores we wish to know about (aka "truth")
parameters - correct answer ✔numerical descriptions (quantities) of a population (of scores) -> "truth"
statistics - correct answer ✔numerical descriptions (quantities) of a sample of scores -> "reality"
µ formal definition - correct answer ✔E(X)
µ computational definition - correct answer ✔summation of (x)/n
σ² computational definition - correct answer ✔summation of (x-mu)^2/n
σ² formal definition - correct answer ✔E(x-mu)^2
nominal - correct answer ✔unordered categories
ordinal - correct answer ✔ordered categories
interval - correct answer ✔ordered categories + equal spaces
, ratio - correct answer ✔ordered categories + equal spaces + true zero
formula for a z-score - correct answer ✔(x-mu)/sd
definition of a z-score - correct answer ✔converting an X from its original units to the number of
standard deviations it is from the mean
formula for a 1-group z-test statistic - correct answer ✔(xbar-mu)/true standard error of the means
formula for a 2-group t-test statistic - correct answer ✔(xbar1 - xbar2) - (mu1 - mu2)/standard error of
the mean differences
unbiasedness - correct answer ✔statistic doesn't under/overestimate the parameter
consistency - correct answer ✔as sample size increases, distribution becomes more compact
efficiency - correct answer ✔going for the parameter that has the least variability (mean)
Central Limit Theorem - correct answer ✔tells us the shape of most sampling distributions (we can
assume it is normal if there is a large enough sample size)
z = 1 - correct answer ✔34.13%
z = 2 - correct answer ✔47.72%
z = 3 - correct answer ✔49.87%
