Systolic blood pressure is normally distributed with a mean of 120 mm Hg and a standard deviation of 10.
4. What pe rce ntage of pe ople in a population se le cte d at random w ould be e x pe cte d to hav e sy stolic blood
pre ssure at or abov e 140 m m Hg?
(A) 1.9%
(B) 2.5%
© 13.5%
(D) 34.0%
(E) 64.2%
--i kind of understand this but may be i'm having a mind block and am not able to grasp it fully please can someone explain--
thank you...
K so asking anyone above 140 so at 140 would be 2 SD cuz mean is 120 with SD of 10 so it will take 2 SD to get to 140 so according to the Gaussian curve ( 50% mean plus 2 SD would be 50+34+13.5=97.5 would be at. 140 since asking above 140 then subtract by 100-97.5=2.5 so 2.5 would have systolic pressure above 140. Hope this helps!!!!
if question ask, what % of people has blood pressure below 100 mm Hq? when mean is 120 and SD is 10.
So would be two SD below so would still be 2.5%
thanks lithium...so for every q that is needing the use of the gaussian curve we have to add the mean and the values for the standard deviation and subtract from 100?
What about the 0.15% value? do we ever need to use it..
thanks..
Np!! Ya I doubt tht they would make u use .15 only way tht would be if it was 3 SD ya bit if it is below SD tht u don't need to subtract by 100 like tht other example u take the mean which is 50- 2SD would be 50-34-15.5=2.5 would have bp below 100. The whole Gaussian curve is equal to 100. Simple way if u look the curve go to 2SD above wat ever % after have is the Answer tht remaining answer to ur 1st question would be like 2.4+.15=2.5 got it hope it helps if not email me at bhavin_engr
continuing the above question.
what % of people has blood pressure below 110 mm Hq?
Thts 1 SD below would be 16% below 110
i m doing it like this,can someone tell me ,if this is correct??
it's 2SD,so 95%
100-95= 5
so 2.5 on each side..