Normal Distribution &
Statistics – Study Guide,
Z-Scores, Practice
Questions & Answers
Updated Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, density curve mathematical model for the distribution of the variable
-on or above the horizontal axis
-always has an area of 1
-area under the curve tells you the proportion of all observations that fall
within that interval
what is on the y axis w density curve? frequency
median of a density curve is the equal-areas point, that is, the point that divides the area under the
curve in half
mean of a density curve the balance point, that is,the point at which the curve would balance if
made of solid material, denoted by µ
standard deviation of a density curve measures how widespread are the values of the distribution, denoted by
greek σ
mean and SD for actual observations representations x bar (mean)and s (standard deviation) for sample data
mean and SD of the actual distribution (population) (mu) µ and (sigma) σ
normal distribution characterized by its mean and SD- can give you everything you need to
know in a normal distribution
-unique mode, the mean, and median are all equal to mu
-inflection points between mu and sigma (concave) and convex everywhere
else
-gives us a bell-shaped curve
formula for normal distribution
68-95-99.7 rule -68% of observations fall between sigma and mu
-95% fall between 2mu of sigma
-99.7% of observations fall with 3 standard deviations of the mean
Statistics – Study Guide,
Z-Scores, Practice
Questions & Answers
Updated Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
, density curve mathematical model for the distribution of the variable
-on or above the horizontal axis
-always has an area of 1
-area under the curve tells you the proportion of all observations that fall
within that interval
what is on the y axis w density curve? frequency
median of a density curve is the equal-areas point, that is, the point that divides the area under the
curve in half
mean of a density curve the balance point, that is,the point at which the curve would balance if
made of solid material, denoted by µ
standard deviation of a density curve measures how widespread are the values of the distribution, denoted by
greek σ
mean and SD for actual observations representations x bar (mean)and s (standard deviation) for sample data
mean and SD of the actual distribution (population) (mu) µ and (sigma) σ
normal distribution characterized by its mean and SD- can give you everything you need to
know in a normal distribution
-unique mode, the mean, and median are all equal to mu
-inflection points between mu and sigma (concave) and convex everywhere
else
-gives us a bell-shaped curve
formula for normal distribution
68-95-99.7 rule -68% of observations fall between sigma and mu
-95% fall between 2mu of sigma
-99.7% of observations fall with 3 standard deviations of the mean
