Ch 7 Statistical Data Treatment and Evaluation Flashcards
is the range of values within which the
population mean m is expected to lie
with a certain probability.
Confidence interval
the limits of the interval
Confidence limit
the probability
that the true mean lies within a certain
interval and is often expressed as a
percentage.
Confidence level
Formula for confidence interval
CI for µ = x̄ ± zσ/ √N
The t statistic is often called
____________. Student was the
name used by W. S. Gossett
when he wrote the classic paper
on t that appeared in 1908
Student’s t
Formula for t stat for a single measurement with result x
t = x - µ/ s
Formula for t stat for a N measurement
t = x̄- µ/ s/√N
postulates that two
or more observed quantities are the
same.
Null hypothesis
we use a statistical __________
to draw conclusions about the population mean m and its nearness to the known
value, which we call m0.
hypothesis test
If a large number of results are available so that s is a good estimate of s, the ______ is
appropriate.
z test
we can reject for either a positive value of z or for a negative value of z that exceeds the critical value. This is called a _____________ since rejection can occur for results in either tail of the distribution.
two-tailed test
For a small number of results, we use a similar procedure to the z test except that the
test statistic is the
t test
uses the same type of procedure as the normal t test except that we
analyze pairs of data and compute the differences, di. The standard deviation is now
the standard deviation of the mean difference.
Paired t test
Comparing the means of more than two samples to determine whether differences in the
means are real or the result of random error. This process is known as
Analysis of variance
The probability
that a result is outside the confidence interval is often called the
significance level
Founded the t test
William Gossetttes
t test is now often called
Student’s t
If it were confirmed by further
experiments that the method always
gave low results, we would say that
the method had a
negative bias
Bias formula
µB - µo
A___________ occurs when Ho is
rejected although it is actually true.
In some sciences, it is called
type I error; false negative
A___________ occurs when Ho is accepted and
it is actually false.
In some sciences, it is called
type II error; false positive
In _____ procedures, we detect difference in several population means by comparing
the variances.
ANOVA
The basic principle of ____is to
compare the variations between the
different factor levels (groups) to that
within factor levels.
ANOVA
By dividing the sums of squares by their corresponding degrees of freedom, we
can obtain quantities that are estimates of the between-groups and within-groups
variations.
mean square values
