Definitions
What is the science of conducting studies to collect, organize, summarize, and draw conclusions from data?
Statistics
Find the median in the data set.
684, 764, 656, 702, 856, 1133, 1132, 1303
810
If two data groups have the same mean, does that mean that their spread/variation is the same?
No, the means can be equal but the spread is different
Bar graphs can be drawn by using vertical or horizontal bars.
True.
It doesn't matter which direction bar graphs are drawn
What are the boundaries for 7.7-10.3?
7.65-10.35
Subtract .05 from lower number and add .05 to upper number
What is the difference between a sample and population?
Sample = group of subjects selected from the population
Population = all subjects being studied
Find the mode(s) of the data set.
66, 23, 10, 10, 34, 34, 100
10 and 34
Since there are two modes, this makes the data set bimodal
What are the three ways used to measure the spread of a data set?
1. Range
2. Variance
3. Standard Deviation
A biased sample is a sample that does not represent the population.
True
What is the difference between the results obtained from a sample and the results obtained from the population from which the sample was selected?
Sampling Error
Random, Systematic, Stratified, Cluster, Convenience
Stratified
Find the mean number of sales in millions for a donut store.
$221, $239, $262, $281, $318
$264.2 MILLION
Find the range of the data set.
100, 30, 25, 87, 99, 8
92
In the construction of a frequency distribution, it IS a good idea to have overlapping class limits.
FOR EX : 5-10, 10-15, 15-20, etc.
FALSE
Classes should not overlap, as it would be hard to discern where to put 10 since it would technically fit in two classes. You should use boundaries.
1
What is the difference between an independent and dependent variable?
Independent = variable being manipulated by researcher
Dependent = outcome variable
Find the midrange of the data set.
76, 100, 45, 20, 77
60
Find the variance of the data set.
10, 60, 50, 30, 40, 20
291.7
The height of a basketball player or temperature in a room is an example of a continuous variable.
True
Continuous means that it could contain a decimal and fraction, discrete means it has to be a whole number since it is a number that can be counted.
If a graph is negatively skewed, does that mean the tail is longer on the right or left?
What graph represents the cumulative frequencies for the classes in a frequency distribution?
Ogive
An instructor grading rubric is the following : Exams = 20%, Paper = 30%, and Final = 50%. If a student got an 83 on the exam, 72 on the paper, and 90 on the final, what was the student's final average. USE WEIGHTED MEAN
83.2
Find the standard deviation of the data set.
10, 60, 50, 30, 40, 20
17.1
Keeping the width of each class the same is not important when constructing a frequency distribution.
False
The class width should be the same for all classes so you can accurately see how many data values appear in it.
Match the following variables with the appropriate level of measurement (either nominal, ordinal, interval, ratio)
1. Ages of instructors at your college
2. Occupations of students who work part time after school
3. Lowest night-time temperatures in December in a large city
4. Rating of medical doctors at a hospital
1. Ratio = ages can be zero, half, or 0
2. Nominal = just naming the jobs of students
3. Interval = can be half, fractions, but no true zero; can't have truly zero degrees
4. Ordinal = can put them into rankings but differences aren't as precise (can be ordered but there is variation among individuals of each ranking