So for i) mean is 83.95/8 = 10.49 sum of squares: all of the x values squared is 881.2119 881.2119 - 8 x 10.49^2 = 0.8911 0.8911/7 = 0.1273 square root of this is 0.357 so standard deviation is 0.357
Is that the correct answer?
No :/ but that's the same answer I got! The answer is 0.193
Lol, I'd say that it won't be too difficult! Not much more they can ask, take a look at the 2011 june series which is one of the harder ones, if you master that you' ll get an A for sure!
I didn't quite master it, but I got an A so hoping for the best!!
Could someone tell me the reasons as to why median mean midrange etc are better in certain situations? EG the questions where it asks you: "which would you recommend to measure the central tendency of the data?"
Could someone tell me the reasons as to why median mean midrange etc are better in certain situations? EG the questions where it asks you: "which would you recommend to measure the central tendency of the data?"
Median, this is a good when there is outliers, as outliers have NO effect on the median, as it's the middle value, so a really high/low value will not affect this average, so recommend the median when outliers are involved.
The Mean is also good if the data is condensed, however it IS affected by outliers also, although outliers do not affect it as much as the Mid Range. This is usually the best with lots of data with no outliers. I'd recommend the mean when outliers are not involved.
Mid Range is only good if the data is condensed, as it involves the highest value & lowest value, so it's bad if there is a high range, as outliers affect the mid range badly. Recommened this or the mean when NO outliers are involved.
Mid Range is only good if the data is condensed, as it involves the highest value & lowest value, so it's bad if there is a high range, as outliers affect the mid range badly. Recommened this or the mean when NO outliers are involved.
Thank you! Exactly what I needed Don't forget about how the skewness affects it too.
Lol, I know the formulas for it & can do it, but I'm always paranoid & seem to make lots of mistakes in that section! I don't like Probability & the Null Hypothesis stuff
Median, this is a good when there is outliers, as outliers have NO effect on the median, as it's the middle value, so a really high/low value will not affect this average, so recommend the median when outliers are involved.
The Mean is also good if the data is condensed, however it IS affected by outliers also, although outliers do not affect it as much as the Mid Range. This is usually the best with lots of data with no outliers. I'd recommend the mean when outliers are not involved.
Mid Range is only good if the data is condensed, as it involves the highest value & lowest value, so it's bad if there is a high range, as outliers affect the mid range badly. Recommened this or the mean when NO outliers are involved.
What about the interquartile range, variance and standard deviation? What does the skewness affect?