Exploring Data
A number that describes a population (often unknown).
What is a Parameter?
If a study lacks random assignment what can’t we do?
What is..
Establish cause-and-effect
This type of distribution represents the probability of a first failure after a consecutive number of successes.
What is..
geometric distribution.
If the P-value < α then we…?
What is..
Reject Ho.
The Chi-Square test that determines if there is an association between two categorical variables.
What is the Chi-Square test of Independence?
This type of variable includes names or symbols of objects, such as "Type of Pet" or "Hair Color".
What is a categorical variable?
When some groups of a population are not covered in a sample.
Undercover age.
Calculator function for normal area.
Normalcdf
The attendance office at Lincoln High wants to know if seniors skip more school days in the second semester vs. first semester. 32 seniors are randomly selected, and their amount of absences were recorded in days for first and second semester. (semester 1-semester 2)
What are both Hypotheses?
What is?
Ho: μdiff=0
Ha: μdiff<0
A correlation (r) value of 0 indicates this type of relationship.
What is no linear relationship?
Similar to a bar chart, this graph displays continuous data by grouping values into bins with no margins between them.
What is a histogram
Dividing the population into groups and sampling all individuals in randomly selected groups.
What is
cluster sampling
Given event A, this equation gives the probability that A will not occur.
What is..
1-P(A)
Do the normal condition check.(n=32)
What is?
B/c n=32 is equal to or greater than 30 it meets CLT, it is approx. normal.
For a skewed distribution, this measure of spread is preferred over standard deviation...
What is the Interquartile Range (IQR)?
If a data set is skewed to the right, what is the relationship between the mean and the median, and which is generally preferred as a measure of center?
The mean is greater than the median, and the median is preferred.
A study in which neither the subjects nor the researchers measuring the responses know which treatment was received.
What is a Double-Blind Study?
The condition for checking independence of two events, A and B.
What is P(A and B)= P(A)P(B)
OR
P(B given A)= P(B)?
Find t if the mean=21, SD=3.6, and n=32
t=33
This type of error occurs when you reject a true null hypothesis.
What is Type I error
What is the standard deviation used to calculate the z-score of a sample mean?
The Standard deviation of the sampling distribution
(sigma/square root of n)
Use enough experimental units in each group so that any difference in the effects of the treatments can be distinguished from chance differences between groups.
What is replication.
If two events, A and B, are mutually exclusive (disjoint), what is P(A l B)?
What is 0?
Find confidence intervals if CL=95%. (Mean=21,SD=3.6, n=32)
(19.7,22.3)
What is the critical value for a 95% confidence interval for a mean.
What is ...
t*=1.96