question 6 core, vcaa 2009

[dfgjgddjidfg]

Having difficulty finding the median upper quartile and lower quartile of the histogram

[StumbleBum]

To find the median value will be the middle value of the data set, we will use the formulae    so it will be    so it will be the 87th value.

Now we need to find how many values lie in each discrete value on the histogram.

so for the the discrete value of 2, 17% of the data holds that value; or if we repeat this for all discrete values we get:

 

Now, once we have this, we find the 87th value. This would lie in 6th discrete data column.

Then for the lower quartile, we take one from the middle value so 86 and divide this by 2 which is the 43rd value. The upper quartile will then correlate to the 131st value.

so the lower quartile would correlate to the 3rd discrete data column and the upper quartile would correlate to the 7th data column.

Then, putting all this together the five number sumary would be and the boxplot would be B.

[dfgjgddjidfg]

thanks alot, quite time consuming for one question

[StumbleBum]

thanks alot, quite time consuming for one question

Well you can actually do it by recognition and realise that B is the only possibility that closely fits the data. That way above is just the mathematical approach to be 100% sure.