Numerical Summaries In Stats Flashcards
What is the mean
The mean is the average
What is the difference between a population mean and a sample mean?
A population mean is called a parameter, and a sample mean is called a statistic. The parameter is often determined by making an inference based on the statistic.
How can you think about the mean and median to remember the difference when looking at a histogram?
Mean is the balancing point of the histogram whereas the median is the splitting in half part of the histogram.
What is the median?
The median is the middle number. It always splits the data in half. It can be found using the formula (n+1)/2
What is the mode?
The mode is the most common or what is occurring the most. It is always the peek of a histogram and it is used with categorical data
Why dont we always use the mean?
It is not RESILIENT , it is impacted by skewness and outliers
When they say the average teenager are we taking about mean median or mode.
It all depends, if we are taking about the heights of an average teenager which would be quantitative data. Whereas if it was asking the favorite singer of average teenager we would be looking at the mode to show who is liked the most. If you are taking about the average income we would most likely use the median.
What is a clear example of when the mean would change but the median would not
Ask 8 people for money in their pocket:
1,2,2,5,5,8,8,9
Mean: 5
Median: 5
But… imagine you run into someone who just won money at a casino and the data looking like this
1,2,2,5,5,8,8,9000
Mean:1000
Median:5
The mean was easily changed because of one person’s data was much larger than the others. This causes the new mean to not be a accurate because out the outlier. However the median stayed the same.
How are the mean median and Mose positioned in a skewed left histogram?
Mean-median-mode (left to right)
HOw are the mean median and mode positioned in a skewed right histogram?
Mode-median-mean
Who chases the tail?
The mean chases the tail…. and outliers
