solve please! (2 Viewers)

[muscleman09]

Hi... someone help out, thanks. still having trouble with this shit! Multi choice 02 paperIn the town of Burrow the ages of the resident are normally distributed. The MEAN age is 40 Years and the standard deviation is 12 years.Approximately what percentage of the residents are younger than 52?

 

[lauragilmour101]

well we know that -1s.d. --> +1s.d is 68%
so from the mean to +1s.d. is 34%

so it will be 50% (up to the mean) plus 34%

hope that explains it for you....

 

[2pmhottest]

answer will be 68/2 + 50 which is34 + 50 =84%. am i correct

 

[PC]

Hi... someone help out, thanks. still having trouble with this shit! Multi choice 02 paperIn the town of Burrow the ages of the resident are normally distributed. The MEAN age is 40 Years and the standard deviation is 12 years.Approximately what percentage of the residents are younger than 52?

I always draw up a number line for the z-scores from -3 to 3 and put numbers according to the mean and standard deviation.

-3 ... -2 ... -1 ... 0 ... 1 ... 2 ... 3
4 ... 16 ... 28 ... 40 ... 52 ... 64 ... 76

Now 52 is 1 standard deviation above the mean, so from 40 to 52 represents half of 68% or 34% of the distribution.
From 40 down is 50% of the distribution.

.: 84% of the residents are younger than 52.

 

[lauragilmour101]

answer will be 68/2 + 50 which is34 + 50 =84%. am i correct

yep!