# Thread: range of one standard deviation from mean

1. ## range of one standard deviation from mean

my question is on part ii, my range ( as shown in the photo), is between 4.52 and 16.28, so my working would be (6+10+4+4)/(6+10+4+4+1) X100% ... the answer given is 72% which is differnt form my answer? which part of my working is wrong ?

2. ## Re: range of one standard deviation from mean

Originally Posted by delso

my question is on part ii, my range ( as shown in the photo), is between 4.52 and 16.28, so my working would be (6+10+4+4)/(6+10+4+4+1) X100% ... the answer given is 72% which is differnt form my answer? which part of my working is wrong ?
why (6+10+4+4)/(6+10+4+4+1) X100% ?
you have found your domain, that is (4.52,16.28)
you need to find the percentage of weeks that fall within this domain. so just check which weeks in your data do fall in this domain. for example, 10 does, 8 does, 7 does, but not 4, not 18, then 9 does, 14 does, and so on... altogether there's 18 that fall in this domain. then 18/25 x 100% = 72%