In reality, a statistician never really has ALL the data. The data is instead taken from a sample of the whole population. If this sample is representative of the entire population, then any statistics based on the sample should be good estimates of the whole but probably not a perfect match. Of course the more data you get from the whole population the better the estimate, but it will always be an estimate unless you census the enitire population.
You can estimate the median and the mean.
You can estimate them both.
You can estimate them both.
The mean deviation from the median is equal to the mean minus the median.
Mean, Median and Mode. They are three kinds of averages.
Quartiles are values that divide a sample of data into four groups containing the same number of observations. You will find details in the related link.
The advantage is that you will have the same number in each quartile. The disadvantage is that you will not be able to determine the median or mean.
You can estimate the median and the mean.
Yes.
You can estimate them both.
You can estimate them both.
There can be any number of sets to satisfy this. The median is the number in the middle and the mean is the average of the numbers. 2,4,6,8,30 is one possible set median = 6 mean = 10
If the distribution is positively skewed , then the mean will always be the highest estimate of central tendency and the mode will always be the lowest estimate of central tendency (If it is a uni-modal distribution). If the distribution is negatively skewed then mean will always be the lowest estimate of central tendency and the mode will be the highest estimate of central tendency. In both positive and negative skewed distribution the median will always be between the mean and the mode. If a distribution is less symmetrical and more skewed, you are better of using the median over the mean.
Yes, you can if you have 3 of the same number. For example, 33, 33, 33. Your mean, median and mode will be 33 for all the them.
Quartiles have nothing to be "solved", but they can be "found" if that's what you mean...
The mean deviation from the median is equal to the mean minus the median.
The answer will depend on what you mean by "solve". Find the mean, median, mode, variance, standard error, standard deviation, quartiles, deciles, percentiles, cumulative distribution, goodness of fit to some distribution etc. The question needs to be a bit more specific than "solve".