peraspera
Forum Elite
Topics: 38
Posts: 233
|
A study of 400 patients with diab. mellitus shows that serum cholesterol levels is a normally distributed variable with a mean of 220 mg/L and standard deviation of 10 mg/dL. Based on the study results how patients do you expect to have serum cholesterol >240 mg/dL in this study?
A. 2
B. 10
C. 20
D. 64
E. 128
Please can someone explain the mathematical procedure,PLEASE
|
| doc179
Forum Guru
Topics: 67
Posts: 1,217
|
B- 10.
This is how I came up to this answer : you should remember the percentage numbers in that standard deviation distribution. 220 is the mean and 10 is the SD and how many above 240? 240 is 2 SDs above 220 which is the mean and above that is 2.5% of 400 which is 10.
|
| robin082006
Forum Hero
Topics: 471
Posts: 5,125
|
excellent explanation doc179
___________________
The Key to Succeed is Patience.
|
| peraspera
Forum Elite
Topics: 38
Posts: 233
|
thanks a lot
I had the same-B, but I needed to be sure in my calculations.
Anyway THANKS
|
| drduck
Forum Guru
Topics: 82
Posts: 529
|
B
|
| paresh1225
Forum Newbie
Topics: 0
Posts: 5
|
ANs is B .. Mean +- 2 sd will cover almost 95 % of popultoin so 220+ 20 ( 2*10) =240 will be among 95% .. and remaing 5% will be divded in to two half those with Chole > 240 and Chole level<200.. so it will 2.5% of total who has chole > 240
|
|
| |
| | | | | | |
