 Hi this is Dr. Don. This question is about taking raw data and constructing a stem and leaf plot and then answering a question about the data. Now we can do this pretty doggone quickly using stat crunch. So let's click on our little rectangle there. We're going to open and stat crunch and so we have our data there and it's pretty straightforward. We just go to graph, look for stem and leaf, select our variable, we can leave everything else alone and click okay. We have a standard stem and leaf plot. Now I would point out to you that the way that stat crunch creates a stem and leaf it divides the stems into two parts from zero to four and then five to nine. So we can see here for the stem nine we've got zero there so that means it's in the zero to the four and then nothing above four. In the ten stem we've got zero for the first half and then the eight so the entire ten stem would be zero eight. Dropping down here to twelve the entire twelve stem would be zero zero four five six seven and by comparing these we can see that option C is the correct one, nine just has zero, ten has zero eight, eleven has zero zero six seven, twelve zero zero four five six seven so that's our correct option there. The second part is what can you conclude about the data and this trips a lot of students up. Alright let's look at the second part now I refreshed and this is a slightly different problem but it's similar to what we just came up with and if we look at the the distribution there the stem and leaf plot we've got the heights from 90 to 150 and they're kind of a nice triangular shaped distribution with an awful lot in the 120 stem. So let's look at these options it appears that most eruptions had the height around 12 well students trip up on that because they see 12 and this column there with a lot of entries but remember that's really 120 not 12 so that's not correct. The next one correctly says 120 but it's wrong because there's just one two three four five six eruptions and the 120 stem 20 minus six is 14 that means there's 14 other places therefore that's not the location of the most. It appears that most eruptions have a height of 211 and 13 and again that's wrong on the surface of it because that's 110 to 130 if they had said between 110 and 130 then you could make an argument that that's correct because there's four eight plus six 14 eruptions in those three stems that would be correct but they said 11 and 13 which is wrong it appears that most eruptions have a height greater than 120 so if we look at 120 and parse it there there's three four seven plus 10 that's 10 eruptions higher than 120 which means there's 10 eruptions low 120 or lower so that's not more that leaves that appears that most eruptions have a height less than 140 we're at 140 there there's three 140 or greater so that means there's 17 less than 140 so that's the correct answer so really read these things closely and then look at your stem and leaf plot and count and don't just jump because one stem appears to have more than the rest and don't get suckered in by the fact that they just use the the prefix there the nine instead of the 90 hope that helps