Test 2 Flashcards
A normal distribution is _metrical, _modal, and the mean, median and mode are _.
SYMmetrical, UNImodal, and the mean, median and mode are EQUAL.
The total area under the standard normal distribution curve is = _?
1
What is the z score?
The Z score is the number of standard deviations from the mean
Sigma signifies…?
Standard deviation of a population
Miu signifies…?
Mean of a population
What percentages of scores lies between -1 and 1 SD in a normal distribution?
68%
What percentages of scores lies between -2 and 2 SD in a normal distribution?
95%
What percentages of scores lies between -3 and 3 SD in a normal distribution?
99%
What percentages of scores lies in the tails in a normal distribution?
0.5%
The probability is the…?
The probability is the area under the curve.
In the Z-score formula, what does X represent?
X represents the value to be converted.
Percentile rank is based on…
The proportion / Z-score.
What is the objective of quantitative sampling?
The objective is to get a lot of information with little cost by using a representative sample. To get the probability
In a quantitative sampling, the sample that is not representative of the population is called…?
The sampling error.
Two examples of quantitative sampling are…?
Simple random sampling and stratified random sampling
In stratified random sampling, the subpopulations are also called…?
Strata
In proportionate stratified random sampling, subpopulations are based to reflect…?
Reflect the proportions in the population
In disproportionate stratified random sampling, subpopulations….?
Compare to an extreme minority.
A small population of under 1000 has a __ sampling ratio of about __%
Larger sampling ratio of about 30%
A moderately large population of about 10,000 has a __ sampling ratio of about __%
Small sampling ratio of about 10%
A large population of over 150,000 has a __ sampling ratio of _%
Very small sampling ratio of 1%
A very large population of over 10 million has a __ sampling ratio of about __%
Tiny sampling ratio of about .025%
An inference is a?
An inference is a theory.
Confidence intervals are presented as a _?
Presented as a range
In a t-distribution, the shape is more _-shaped?
Dome-shaped (as opposed to bell-shaped)
How is the degree of freedom (df) calculated for t-distribution?
n-1
Rounding in t-distribution is up or down?
Round down
How are confidence interval problems’ solutions presented?
The solutions are presented with a range and a full sentence to interpret.
Hypothesis testing is _ testing.
Significance testing.
The null hypothesis is the…?
The null (H0) hypothesis is the currently accepted hypothesis.
The research hypothesis is the…
The research hypothesis (Ha) is the new hypothesis that we want to test.
What are the steps in the Five-Step Model?
1) Identify
2) 1 or 2 tailed + H0&Ha
3) State sampling distribution & critical values
4) Identify formula & test statistic(s)
5) Interpret
A one-sample Z-test is used when…?
A one-sample Z-test is used when we want to compare population to sample.
When it’s a 2-tailed test, we must give _# t-__.
In a 2-tailed test, we must give 2 t-criticals.
In a 2 sample t-test, how is the degree of freedom (df) determined?
df= (n1+n2)-2
The chi square is a test of…
The chi square is a test of significance based on crosstabulation tables
In chi square, O means _ and E means _.
O means “observed” and E means “expected”.
The degree of freedom for chi square is:
df= (i-1)(j-1)
E is calculated using:
E= (row total X column total)/total # surveyed
Chi square tests are always _-tailed
Chi square tests are always ONE-tailed
In chi square, H0 is the variables are __ and Ha is the variables are __.
H0 is the variables are independent and Ha is the variables are dependent (there is a significant relationship).
Correlation can only be used with ___ and ___ data.
Ordinal treated as interval and interval.
Testing correlation is always _-tailed
Testing correlation is always TWO-tailed
What is the degree of freedom for Pearson’s r?
df = n-2
What are the strengths or correlation?
- 00-0.29: weak
- 30-0.59: moderate
- 60-1.00: strong
To draw a regression line, what 2 points are necessary?
The Y-intercept and the intersection of the means are necessary to draw a regression line.
How is the coefficient or determination/non-determination answered?
“_% of the variance in the (y) is explained/explained by something other than by the (x).”
