hey guys it's Kaeleigh this lesson is an introduction to statistics where we'll
cover statistical questions and dot plots let's get started you've probably
heard the word statistics or its abbreviation stats before statistics
help us answer questions like who was one the most times in your video game or
how many times and how fast did I run on different days this week statistics is
the science of collecting organizing analyzing and interpreting data in
statistics data is very very important but how do we collect data there are a
few ways we can run an experiment or have a survey but in both of these ways
of collecting data there is one main thing in common we have to ask a
question when we ask a question to collect data and needs to be a
statistical question a statistical question is one where you expect to get
a variety or a lot of different answers
which of these do you think is a statistical question how tall are
basketball players what time did you wake up this morning how much money do
people typically spend on cars do you play soccer right it's these two here
but how do we know that those are the statistical questions it's because when
we ask them they will provide us with a variety of different answers that we
will use as data whereas these two here can only give us one
answer be careful not to confuse statistical questions with survey
questions if we have a statistical question how tall our basketball players
we will have to take a survey of many different basketball players and ask a
survey question like how tall are you you can think of a statistical question
as one where you would have to ask a lot of different people the same survey
question to collect data but once we have our data like how tall our
basketball players we need to organize it see right now it's just listed
between two brackets but the numbers are all out of order the best way to
organize your numerical data is from least to greatest so we take our at
least point 65 and put it in the beginning and we take our highest value
82 and put it at the end then we can analyze and interpret it one way we do
that in statistics is to display data on a dot plot a dot plot is a type of graph
where each piece of data is displayed as a dot above a number line we stack the
dots on top of each other over the number to show the frequency of the data
the total number of dots on the plot is equal to the total number of values in
our data set by displaying our data in a dot plot we can analyze our data more
easily a dot plot shows us the spread or the range of our data in our case the
heights of basketball players range from 65 inches to 82 inches a dot plot can
also show us the shape of our data ours is asymmetrical that means there's a
different number of dots on either side of the center point
symmetrical dot plots will either be bell-shaped or u shaped but either way
the number of dots is the same on either side of the center point for symmetrical
data in a dot plot we can easily see if we have a peak in our data a peak means
a data point that occurs with the most frequency or the most often than other
data values do you see a peak in our dot plot yeah in our data we see a peak over
81 inches so you can say that a basketball player with a height of 81
inches occurs most often a dot plot will also tell us if there is a cluster a
cluster is when there are a lot of data points within a small interval or a
small range do you see a cluster in our dot plot yeah that's right we have a
cluster in our data between 78 inches and 82 inches so we can say most
basketball players have a height between 78 inches and 82 inches dot plots are
also an easy way to visualize any outliers an outlier is when a data point
is either a much greater or much less than the rest of the data usually
there's a big gap between the rest of the data and an outlier do you see any
gaps an out layer outliers in our data yeah we have an outlier data point over
here at 65 inches so for our data we could say it's not very common or likely
for a basketball player to have a height of 65 inches and now that we've analyzed
our data in our dot plot we can interpret our data this means coming up
with a general answer to our statistical
question remember our question was how tall are basketball players and looking
at our plot we can say most basketball players are around 80 inches
nice job learning about statistical questions and dot plots now practice
what you have learned by doing the online games and activities have fun and
remember to always be clever