qsm+lecture+2sm+lecture+2qsm+lecture+2qsm+lecture+2.ppt

References * MEDIAN is the middle value in a set of numbers when they are ranked in order of magnitude (size). The median value for ratings of the college canteen is 2. If we were to list the ratings for the canteen from highest to lowest can see there are 23 ratings at 3, 34 ratings at 2 and 3 at 1. As there is an even number of numbers the middle value will be the average of 30th and 31st observation. 333333333333333333333332222222222222222222222222222222222111 Hence the median is half of the sum of these two numbers which is (2+2)/2. In the BMSurvey however you will not count anything you will use the formula…….. * MODE is the number/s which occurs the most often in a set of numbers. In the rating of the canteen facilities there were 23 ratings at 3, 34 ratings at 2 and 3 at 1.The modal value of the ratings for the college canteen is therefore the most frequent rating of 2. You can see from this that whatever measure you use the refectory facilities are rated as poor. To do this by formula is again much easier and the steps to the calculation of the mean median and mode you have just done are shown in the notes. * * Now we need to move on to calculating the measures of dispersion which will require us to fill in the boxes shown in blue. * We mentioned in the first lecture that as well as a measure of average we need to know the “spread” of the data. This is known as the measures of dispersion. The two measures we will look at are range and standard deviation. The RANGE is simply the difference between the lowest value and the highest value that is why we use the maximum and minimum value. If we use the assessment results in Law we can calculate MAX and MIN. We then subtract MIN from MAX * STDEVP. This is the second measure of dispersion we will cover in this unit. Standard deviation is a measure of how widely spread our data is dispersed in relation to the mean value of the distributio