The median of a set of data is used for similar purposes as the mean. They both give you a middle number that represents what the set of data fluctuates around. While the mean gives you the exact center, the median simply gives you the middle piece of data. The following is an example of why the median is sometimes more helpful than the mean:
Consider a class of 5 students that take a test that is scored on a scale of 0 to 500. The scores of the students are as follows:
1) 25
2) 120
3) 102
4) 248
5) 500
The mean of the scores is (25+120+102+248+500)/5 = 199
The median of the scores is 120
Looking only at the mean, the teacher may get the impression that the students are more skilled than they really are, since the average score of the class is 40% of the highest possible score. However, one student scored only 49 points higher than the mean and the other 3 didn't get within 70 points of it.
Looking at the median, the teacher sees that another accurate representation of the scores is 120. This is only 24% of the highest possible grade and better represents what most of the class got. Unlike the mean, the median wasn't set deceivingly high by the one student with a perfect score.
It is misleading to use the mean as a descriptor of a data set when the median or mode would be more representative of the data set as a whole.
The answer depends on the type of data. The mean or median are useless if the data are qualitative (categoric): only the mode is any use. The median is better than the mean is the data are very skewed.
You use mean when you want to find the average of data. You use median to find the middle of a piece of data, ordered from least to greatest. If there is 2 medians, then find the average of those 2 numbers. You use mode when you are trying to figure out the most common piece of data. There can be more than 1 mode.
You will need to put the un-grouped data in ascending or descending order. If you have an odd number of data values the formula for the median value is (n+1)/2. Example my data in ascending order is 0, 2, 4, 5, 7, 8, 9. I have 7 data values. The median is the value (7+1)/2 = 4th value from left or right which is 5. For an even number of data values, you will need to calculate the median and it may not be a data value. It will be the mean of the two center values. Use the formula n/2 to get the left most value. Example my data in ascending order is 0, 2, 4, 5, 7, 8. I have 6 data values. The left most value I will use to calculate the median is 6/2 = 3rd. The 3rd value from the left is 4. The next value is 5. Median is (4+5)/2 = 4.5.
The median is the middle number of a set of numbers. But because there are ten numbers in this case you can't have a middle one. Sometimes in this case people will use the mean which is the sum of the list divided by the number of items in the list. Using this method the median is 28.5
mean is the average of numbers in the data set mode is the most frequently occurring value in a data set and median is the middle number of the data set so you would use mean
You would use the median if the data were very skewed, with extreme values.
It is misleading to use the mean as a descriptor of a data set when the median or mode would be more representative of the data set as a whole.
The median is a measure of central tendency. In a set of data, it is the value such that half the observed values are larger and half are smaller.
The mean is used for evenly spread data, and median for skewed data. Not sure when the mode should be used.
Roughly speaking, finding the third quartile is similar to finding the median. First, use the median to split the data set into two equal halves. Then the third quartile is the median of the upper half. Similarly, the first quartile is the median of the lower half.
Yes, the median is always a number. For qualitative data, use the mode for a measure of center.
You can use them to describe the central tendency of the data but no more than that.
The answer depends on the type of data. The mean or median are useless if the data are qualitative (categoric): only the mode is any use. The median is better than the mean is the data are very skewed.
It is a statistical measure that helps you understand the sample/population data.
Yes. If you have very high or very low outliers in your data set, it is generally preferred to use the median - the mid-point when all data points are arranged from least to greatest. A good example for when to avoid the mean and prefer the median is salary. The mean is less good here as there are a few very high salaries which skew the distribution to the right. This drags the mean higher to the point where it is disproportionately affected by the few higher salaries. In this case, the median would only be slightly affected by the few high salaries and is a better representation of the whole of the data. In general, if the distribution is not normal, the mean is less appropriate than the median.
When you want to know the piece of data that falls right in the middle.