STAT 330 NDSU EXAM WITH
COMPLETE SOLUTIONS
A portion of the population (students in STAT 330)
(p, x, s, n, xbar) - ANS-Sample Definition
Total set of observations that can be made (every single person in the world)
(P, X, N, µ,σ,σ²) - ANS-Population definition
P - ANS-population proportion
µ - ANS-population mean
µ = ∑x/N - ANS-population mean formula
σ - ANS-population standard deviation
σ=√∑(xi-µ)²/N
or σ= √σ² - ANS-population standard deviation formula
σ² - ANS-population variance
σ²=∑(x-µ)²/N - ANS-population variance formula
standardized value that measures how many standard deviations x is from the mean
under the normal curve - ANS-z-score
z=(x-µ)/σ - ANS-z-score formula
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x - ANS-sample mean
_
x= (∑Xi)/n - ANS-sample mean formula
(s) the average distance of the data from the mean - ANS-sample standard deviation
(s²) - ANS-sample variance
s=√s² or s= √(∑Xi-xbar)²/(n-1) - ANS-sample standard deviation formula
COMPLETE SOLUTIONS
A portion of the population (students in STAT 330)
(p, x, s, n, xbar) - ANS-Sample Definition
Total set of observations that can be made (every single person in the world)
(P, X, N, µ,σ,σ²) - ANS-Population definition
P - ANS-population proportion
µ - ANS-population mean
µ = ∑x/N - ANS-population mean formula
σ - ANS-population standard deviation
σ=√∑(xi-µ)²/N
or σ= √σ² - ANS-population standard deviation formula
σ² - ANS-population variance
σ²=∑(x-µ)²/N - ANS-population variance formula
standardized value that measures how many standard deviations x is from the mean
under the normal curve - ANS-z-score
z=(x-µ)/σ - ANS-z-score formula
_
x - ANS-sample mean
_
x= (∑Xi)/n - ANS-sample mean formula
(s) the average distance of the data from the mean - ANS-sample standard deviation
(s²) - ANS-sample variance
s=√s² or s= √(∑Xi-xbar)²/(n-1) - ANS-sample standard deviation formula
