alanforde800Maximus wrote:A bell curve (Normal Distribution) has a mean of -1 and a standard deviation of 1/8.
How many integer values are within three standard deviation of mean?
a)1
b)2
c)3
d)4
e)5
Mean =
-1
Standard Deviation =
1/8
1 unit of standard deviation BELOW the mean =
-1 -
1/8 = -1 1/8
2 units of standard deviation BELOW the mean =
-1 -
1/8 -
1/8 = -1 2/8
2 units of standard deviation BELOW the mean =
-1 -
1/8 -
1/8 -
1/8 =
-1 3/8
1 unit of standard deviation ABOVE the mean =
-1 +
1/8 = -7/8
2 units of standard deviation ABOVE the mean =
-1 +
1/8 +
1/8= -6/8
3 units of standard deviation ABOVE the mean =
-1 +
1/8 +
1/8 +
1/8=
-5/8
So, all values from
-1 3/8 to
-5/8 are within 3 standard deviations of the mean.
Within this range, there is only
1 integer value: -1
Answer:
A
RELATED VIDEO
- More Standard Deviation:
https://www.gmatprepnow.com/module/gmat ... /video/809Brent Hanneson - Creator of GMATPrepNow.com
