Frequency distribution

[saskura]

hello!
I'm a third year college student... I'm just having trouble upon answering my statistics activity it was all about frequency distribution.
I'm wondering if I'm on the right track, the situation is this:

The numbers of hours sleep in a day of 100 students is listed below:
4,8,6,6,5,4,6,6,7,4,4,7,7,6,6,6,6,4,7,8,8,7,6,8,4,6,8,7,4,6,6,5,2,4,8,7,7,8,4,4,2,8,8,7,6,8,5,8,2,7
7,8,8,8,8,8,8,6,6,7,8,4,7,5,6,7,6,3,4,3,6,7,5,8,8,8,7,7,5,4,4,6,6,7,4,5,8,7,6,4,4,5,6,7,5,6,8,8,7,7

so, first I determine the range:

range=Highest Value - Lowest Value
=8-2
range= 6

then, I solved for number of classes using sturges formula:

k=1+3.322(logn)
=1+3.322(log100)
k=7.64
(round up) therefore k=8

then, the class interval:
i=range/k
=6/8
i=0.75
(round up) i=1

so here's the problem my class interval is 1 so I come up with the classes as follows:

2-2
3-3
4-4
5-5
6-6
7-7
8-8
9-9

I got that list by:

lower limit:
adding 1 to the lowest value;
2+1=3
3+1=4
4+1=5
5+1=6
6+1=7
7+1=8
8+1=9

upper limit
subtracting 1 from the second lower limit then adding one to it:
3-1=2
2+1=3
3+1=4
4+1=5
5+1=6
6+1=7
7+1=8
8+1=9

so I got that classes, I really wonder if I'm on the right track because there was no gap between the classes.
In addition, I have also tried to use "2^k greater than or equal to n" but I still got that kind of classes...
Can somebody help me? Am I correct? or there's something wrong please help me...
I'm really having trouble about this.. thank you in advance...

 

[saskura]

please can anybody help me?

 

[ksdhart2]

Er, sorry, but I'm having trouble figuring out what the actual question you're tasked with solving is. Can you please post the full and exact text of the problem statement, quoting word-for-word if possible? Thank you.

 

[saskura]

Er, sorry, but I'm having trouble figuring out what the actual question you're tasked with solving is. Can you please post the full and exact text of the problem statement, quoting word-for-word if possible? Thank you.

oh.. I'm sorry for that, actually I was tasked to calculate for the measure of central tendency [mean, median and mode] and also measure of position [quartile, decile and percentile] for grouped data. In addition, I was just having trouble upon constructing my frequency distribution table. thanks for the help..I'm hoping that you can help me..

thank you for being a helpful person..

 

[saskura]

I'm so grateful that somebody noticed my post

 

[ksdhart2]

Yeah, posts by new users go into a queue where they're hidden until approved by a moderator. It prevents people from just creating a bunch of accounts and flooding the forum with spam. But, as for the problem, I know of two ways to group data into "classes," depending on whether or not you want data to overlap. Since all the data entries are integers, I think you'd be best served to use non-overlapping groups. I think the only thing I'd do differently is to round the k value down to 7, so that your groups stop at 8 hours. So, the next step would be to make a table, perhaps like so:

2 | 3
3 | 2
...
8 | 24

I might have counted those numbers wrong, so double check for yourself. In any case, once you've got the table, you should be able to find the mean, etc. fairly easily right?

 

[saskura]

Yeah, posts by new users go into a queue where they're hidden until approved by a moderator. It prevents people from just creating a bunch of accounts and flooding the forum with spam. But, as for the problem, I know of two ways to group data into "classes," depending on whether or not you want data to overlap. Since all the data entries are integers, I think you'd be best served to use non-overlapping groups. I think the only thing I'd do differently is to round the k value down to 7, so that your groups stop at 8 hours. So, the next step would be to make a table, perhaps like so:

2 | 3
3 | 2
...
8 | 24

I might have counted those numbers wrong, so double check for yourself. In any case, once you've got the table, you should be able to find the mean, etc. fairly easily right?

I'm so thankful for your help I will do what you do so..