Test 3

Question Answer
6.2
uniform distribution values spread evenly over the range of possibilities
Standard normal distribution normal probability distribution with mean=0 and stand. deviation=1
normal cdf probability
inv.norm. z-score
6.3
z score formula x-mean/stand. dev.
Standard error of the mean o
x
mean/square root of n
Sample of Values _
x-mean/stand.Dev./Sqare root of n
7.2
Point Estimate single value(or point) used to approximate a population parameter
Confidence Interval range of values used to estimate the true value of a population parameter
Confidence level probability 1-a
critical value number on the borderline seperating sample statistics that are likely to occur from those that are unlikely to occur(z
a/2)
Margin of error denoted by E,maximum likely difference
Round off rule-CI 3 digits
Round off rule-Sample size larger whole number, can't have half a person
sample size for population mean n=[za/2o
/e]^2
Degrees of Freedom number of sample values that can vary after certain restrictionsw have been imposed on all data values
Degrees of freedom formula n-1
Zinter mean is known and n>30
Tinter mean NOT known and n>30