Okay, So in this problem, we want to try a different approach to computing the media. So it won't be exactly the median, but we want to try if we can get good approximation of the median using a frequency table. So here we have the frequency table off the time, the waiting time in seconds at a fast food restaurant. And we need to identify what's the median class first? So what is the median class? Well, it's the class that contains the media, so we have. In total, we have 50 50 different waiting times. So 11 plus 24 is 35 plus 10 is 45 3 48 plus 2 50. So we have 40 50 different observations and where is the medium? Well, the median would be in the class with the 25th observation. So we have 11 observation in the first class and 24 in the second class. That mean in total we have 35 of observation in that in the first two class class is therefore the the media is in the second class. So the media, the medium classes that class 125 2nd 274 seconds. Therefore, the lower limit. The lower limit of medium class is 125. So we have the lower land. Was the class with? Well, it's the number of of information in the class, the number of the range covered by the class. So in that case, we cover 50 seconds. So the class with is 50. We have fish and what is N and is the total frequency. So ah, and is 50 because we have 50 different observation. Mm. Is the number of frequencies, uh, in the class, the some of the frequencies before off the classes that precede the median class. So the medium, the medium class is 125 174. There, for the only class that precedes it is 75 to 124 which has 11 entries, 11 values. So and the sum of 11 added to nothing is 11. So we have em and, um, the frequency of the medium class. So frequency of eso we have basically and and m and the frequency of medium classes than them is what what you would find in the table. So it's, um, 24. So we have 24 values in the 125 and 174 class, so we can put everything in this formula we have here. So 124 101 125 plus 50 times 50 plus one, divided by two minus 11 plus one, divided by 24. And let me zoom out a little bit to give myself room to breathe. Yes, that seems a bit better, Which gives us a median of 153 0.125 eso That's the media using this formula based on the frequency table. And if, um if you use the data set in Excel and you want to find the true median, uh, so you simply use this command. So the data, the full data set is available on the book website, so it's a two to a 51 and that is 150 0.2 for all Together. Those two there there's, like 2.5 seconds 2 to 3 seconds difference in the two median, which means they're basically so that the formula we used with the frequency table is accurate is accurate enough. Although you would never use this method if you had access toe all the data. Like if you have data set 25 available to you you for any purpose, you might need the median. You will always compute the rial media Theis formula that we use here is used for only if you only have the frequency table. It's the only data available to you then that that formulas Good enough. But of course, if you have the raw data, the full the full data set, you will compute the rial media. Yeah.