Measures of Central Tendency
In a dot plot, this measure of central tendency would have the most dots stacked above it.
What is the mode?
What is a simple random sample?
Each member of the population has an equal chance of being selected (like drawing a name out of a hat)
These are two main differences between a bar graph and a histogram.
What is:
Histogram: bars touch, interval data
Bar graph: bars don't touch, categorical data
Which type of distribution has all the bars at the same level?
Uniform
How do we find the mode of a data set?
Find the number that appears most often
It is found by adding every number in a data set and dividing that sum by the number of data points in the set.
What is the mean?
What is a voluntary response sample?
When members of the population who have chosen to respond are surveyed
What is the difference between discrete and continuous data?
Discrete can only be whole numbers, continuous can be decimals.
Which type of distribution has the highest frequency in the middle?
Normal
How do we find the mean of a data set?
Add all the numbers together and divide by the number of numbers
Adding a number in a data set that is much greater than the other numbers would do this to the mean.
What is increase?
What is a cluster sample?
When the population is divided into groups and you ask every member of a certain number of groups
Primary = you make the question and get the answer for yourself
Secondary = someone else gets the information/does the work for you
Which type of distribution has the lowest frequency in the middle?
Bimodal
What's the formula we used to find the median number position?
(n+1)/2
The median of the following data set:
6, 3, 7, 8, 1, 4, 2, 5
What is 4.5?
What is a systematic sample?
When you choose every nth person/object to be a part of your research
List the three different data types.
Discrete, continuous, and categorical
How can we tell if a graph is left skewed distribution?
The high bars are on the right/low bars are on the left
How many modes can one data set have?
One, none, or as many as needed!
The names of the measures of central tendency that we discussed in class.
What are mean, median, and mode? (NOT range)
What is a stratified random sample?
When the population is divided into subgroups and you choose a random sample proportional to each group (i.e. if you had 10 grade nines and 20 grade elevens and wanted 10% of each you'd ask 1 grade nine and 2 grade elevens)
This graph is best to display data represented by intervals.
What is a histogram?
What is an outlier?
A number that is way outside the data set: an oddball number
What's a better measure of data: mean or median?
Median