OCTH 245: Final Exam UPDATED ACTUAL
Questions and CORRECT Answers
3 types of possible statistics - CORRECT ANSWER - 1. Descriptive
2. Inferential
3. Correlational
Descriptive Statistics - CORRECT ANSWER - -summarize or describe data
-reduce large sets of data into understandable, meaningful pieces
-includes measures of central tendency and measures of variability
Inferential Statistics - CORRECT ANSWER - -allow us to infer or draw conclusions about a population based on a
sample of data from the population
-also used to look at group differences
Correlational Statistics - CORRECT ANSWER - -strength of the relationship between two variables
Frequency Distributions - CORRECT ANSWER - a table or figure that shows the number of data observations that
fall into specific intervals
Data are displayed/described through ___________ - CORRECT ANSWER - frequency distribution
How can data be displayed? - CORRECT ANSWER - table, chart, or figure
For example: histogram, bar chart, pie chart, line chart
What are the 3 main Measures of Central Tendency - CORRECT ANSWER - -mean
-median
-mode
Mean - CORRECT ANSWER - -the average calculated by adding all values and dividing by # of observations
-the sum of all values divided by the total number of values
Median - CORRECT ANSWER - -middle of ranked scores
-middle number in an ordered dataset
This type of measure of central tendency is used when the data is skewed - CORRECT ANSWER - median
Mode - CORRECT ANSWER - most frequently occurring score
This type of measure of central tendency is used when the data is bi-modal - CORRECT ANSWER - mode
Negative Direction for measures of central tendency (picture) - CORRECT ANSWER -
Positive Direction for measures of central tendency (picture) - CORRECT ANSWER -
What is measures of central tendency? - CORRECT ANSWER - describe the center point of data by using a single
value (for continuous values)
What is the central tendency normal curve? - CORRECT ANSWER - symmetrical bell-shaped curve
mean, median, and mode are all equal and located at the center of the curve (all have the same value)
, What do you call a curve that is NOT normal or symmetrical? - CORRECT ANSWER - skewed
Measures of Variability - CORRECT ANSWER - -also called as Measures of Dispersion
-describe how far a data set has strayed away from the mean
What are the measures of variability? - CORRECT ANSWER - -range
-variance
-standard deviation
Range - CORRECT ANSWER - describes how far a data set has strayed from the mean
Variance - CORRECT ANSWER - - reflects the variation of the distribution within a full set of scores
- describes the relative distance between data points in a set and the mean of the set
-used to calculate the standard deviation
Standard Deviation (SD) - CORRECT ANSWER - -spread the data of the mean
-squared root of the variance
-most commonly used measure of variance
Confidence Intervals (CI) - CORRECT ANSWER - -how close the mean of the sample fits with the mean of the
population
-a type of estimate of population parameter
-used to indicate the reliability of an estimate
What are categorical variables? - CORRECT ANSWER - -variables that represents categories or groups
-can be nominal or ordinal
Categorical variables: examples of nominal - CORRECT ANSWER - -gender, ethnicity
Categorical variables: examples of ordinal - CORRECT ANSWER - education level, SES
Null hypothesis - CORRECT ANSWER - -statistical hypothesis that assumes that the observation is due to a
chance factor
-denoted by (H0): μ1=μ2 (mean1=mean2) **subscript 0**; shows that there is no difference between the two population
means
Alternative hypothesis - CORRECT ANSWER - -shows that observations are the result of a real effect
- (H 1 or H A ) **subscript for 1 and A**
-the sample observations are influenced by some non-random cause
Level of significance - CORRECT ANSWER - -refers to the degree of significance in which we accept or reject
the null-hypothesis
Why do researchers typically select a level of significance of 5% in hypothesis testing? - CORRECT ANSWER -
to minimize the probability of committing a Type I error
What is the term for rejecting the null hypothesis when it is actually true? - CORRECT ANSWER - Type I error
Questions and CORRECT Answers
3 types of possible statistics - CORRECT ANSWER - 1. Descriptive
2. Inferential
3. Correlational
Descriptive Statistics - CORRECT ANSWER - -summarize or describe data
-reduce large sets of data into understandable, meaningful pieces
-includes measures of central tendency and measures of variability
Inferential Statistics - CORRECT ANSWER - -allow us to infer or draw conclusions about a population based on a
sample of data from the population
-also used to look at group differences
Correlational Statistics - CORRECT ANSWER - -strength of the relationship between two variables
Frequency Distributions - CORRECT ANSWER - a table or figure that shows the number of data observations that
fall into specific intervals
Data are displayed/described through ___________ - CORRECT ANSWER - frequency distribution
How can data be displayed? - CORRECT ANSWER - table, chart, or figure
For example: histogram, bar chart, pie chart, line chart
What are the 3 main Measures of Central Tendency - CORRECT ANSWER - -mean
-median
-mode
Mean - CORRECT ANSWER - -the average calculated by adding all values and dividing by # of observations
-the sum of all values divided by the total number of values
Median - CORRECT ANSWER - -middle of ranked scores
-middle number in an ordered dataset
This type of measure of central tendency is used when the data is skewed - CORRECT ANSWER - median
Mode - CORRECT ANSWER - most frequently occurring score
This type of measure of central tendency is used when the data is bi-modal - CORRECT ANSWER - mode
Negative Direction for measures of central tendency (picture) - CORRECT ANSWER -
Positive Direction for measures of central tendency (picture) - CORRECT ANSWER -
What is measures of central tendency? - CORRECT ANSWER - describe the center point of data by using a single
value (for continuous values)
What is the central tendency normal curve? - CORRECT ANSWER - symmetrical bell-shaped curve
mean, median, and mode are all equal and located at the center of the curve (all have the same value)
, What do you call a curve that is NOT normal or symmetrical? - CORRECT ANSWER - skewed
Measures of Variability - CORRECT ANSWER - -also called as Measures of Dispersion
-describe how far a data set has strayed away from the mean
What are the measures of variability? - CORRECT ANSWER - -range
-variance
-standard deviation
Range - CORRECT ANSWER - describes how far a data set has strayed from the mean
Variance - CORRECT ANSWER - - reflects the variation of the distribution within a full set of scores
- describes the relative distance between data points in a set and the mean of the set
-used to calculate the standard deviation
Standard Deviation (SD) - CORRECT ANSWER - -spread the data of the mean
-squared root of the variance
-most commonly used measure of variance
Confidence Intervals (CI) - CORRECT ANSWER - -how close the mean of the sample fits with the mean of the
population
-a type of estimate of population parameter
-used to indicate the reliability of an estimate
What are categorical variables? - CORRECT ANSWER - -variables that represents categories or groups
-can be nominal or ordinal
Categorical variables: examples of nominal - CORRECT ANSWER - -gender, ethnicity
Categorical variables: examples of ordinal - CORRECT ANSWER - education level, SES
Null hypothesis - CORRECT ANSWER - -statistical hypothesis that assumes that the observation is due to a
chance factor
-denoted by (H0): μ1=μ2 (mean1=mean2) **subscript 0**; shows that there is no difference between the two population
means
Alternative hypothesis - CORRECT ANSWER - -shows that observations are the result of a real effect
- (H 1 or H A ) **subscript for 1 and A**
-the sample observations are influenced by some non-random cause
Level of significance - CORRECT ANSWER - -refers to the degree of significance in which we accept or reject
the null-hypothesis
Why do researchers typically select a level of significance of 5% in hypothesis testing? - CORRECT ANSWER -
to minimize the probability of committing a Type I error
What is the term for rejecting the null hypothesis when it is actually true? - CORRECT ANSWER - Type I error
