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A Normal Probability Distribution has a _
distribution and a skewness measure of _
symmetric, zero
TERM 2
The highest point of the normal curve is at the
_, which is also the _ and _
DEFINITION 2
mean, median and mode
TERM 3
Probabilities for the normal random variable
are given by _
DEFINITION 3
the areas under the curve
TERM 4
Total area under a normal distribution is
always equal to
DEFINITION 4
1, with 0.5 on to the right and 0.5 to the left of the mean
TERM 5
The normal random variable is designated by
DEFINITION 5
"Z", where the mean = 0 and the standard deviation = 1
Z=
x-u/o
TERM 7
Chapter 8
DEFINITION 7
The distribution of the sample mean "x bar" and the sample
proportion, "p hat"
TERM 8
Point estimator
DEFINITION 8
using data from the sample to compute a sample statistic
that represents an estimate of the population parameter,
such as x bar for u (mean), s for o (standard deviation), and p
hat for p (proportion)
TERM 9
If n > or = 30
DEFINITION 9
then the CLT applies and the sampling distribution of the
mean will be approximately normally distributed
TERM 10
However, if the population is KNOWN to be
normally distribution
DEFINITION 10
then the CLT applies for all sample sizes
The standard deviation, or standard error of
proportions, for p^ =
p is knownsquare-root of 1(1-p)/np is unknownsquare-root of
p^(1-p^)/n
TERM 17
Chapter 9
DEFINITION 17
what is an estimator?point estimation of the population
meaninterval estimation of the population meaninterval
estimation of the population mean, small samples or o
unknown precision and sample size: meansestimating the
population proportionprecision and sample size: proportions
TERM 18
A point estimator can be
used
DEFINITION 18
cannot be expected to provide the exact value of a
population parameter
TERM 19
As a result, an interval estimate can be
computed
DEFINITION 19
by adding and subtracting the margin of error to the point
estimate
TERM 20
What do you use if 1. o is known 2. o is not
known, n > or = 30 3. o is not know, n < 30
DEFINITION 20
1. normal distribution2. normal distribution3. t distribution
The margin of error =
E = Z(a/2)*o/square-root of n
TERM 22
Necessary sample size =
DEFINITION 22
IF N IS NOT AN INTEGER, ALWAYS ROUND UPEVEN IF IT IS
73.3, ROUND UPn=(Za/2)^2*O^2/E^
TERM 23
what is the difference between a, the
confidence coefficient, and the confidence
level
DEFINITION 23
a = level of significance, such as 0.05confidence coefficient
= 1-a, or 0.95confidence level = confidence coefficient X
100, or 95%
TERM 24
Normal Probability distributions have a sum of
probabilities = _ and the area under the
distribution = _
DEFINITION 24
