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by kanha81 » Mon Apr 20, 2009 10:42 am
A vending machine is designed to dispense a ounces of coffee into a cup. after a test that recorded the number of ounce of coffee in each of 1000 cups dispensed by the vending machine the 12 listed amounts below, in ounces were selected from the data. If the 1000 recorded amounts have a mean of 8.1 ounces and standard deviation of 0.3 ounce, how many of the 12 listed amounts are within 1.5 standard deviation of the mean?

7.51 8.22 7.86 8.36
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53

a) four
b) six
c)nine
d)ten
e)eleven

OA [spoiler][E][/spoiler]
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by dumb.doofus » Mon Apr 20, 2009 10:50 am
According to question
Avg = 8.1
SD = 0.3
1.5 SD = 0.45

So essentially find all those values that are with in 7.65 and 8.55

So answer is E
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by Musiq » Mon Apr 20, 2009 10:52 am
We are looking for all numbers that fall within the 1.5 standard deviations from the Mean parameter.

The parameters are Mean +or- (1.5) * ( Standard Deviation) or 8.5 + or -.45

Or count all values of the 12 presented that lie between 7.65 and 8.55

Answer = E
Last edited by Musiq on Mon Apr 20, 2009 12:54 pm, edited 1 time in total.
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by dumb.doofus » Mon Apr 20, 2009 11:04 am
Musiq wrote:We are looking for all numbers that fall within the 1.5 standard deviations from the Mean parameter.

The parameters are Mean +or- (1.5) * ( Standard Deviation) or 8.5 + or -.45

Or count all values of the 12 presented that lie between 7.55 and 8.55

Answer = E
Should be 7.65 and not 7.55
8.1-0.45 = 7.65
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by Musiq » Mon Apr 20, 2009 12:55 pm
dumb.doofus wrote:
Musiq wrote:We are looking for all numbers that fall within the 1.5 standard deviations from the Mean parameter.

The parameters are Mean +or- (1.5) * ( Standard Deviation) or 8.5 + or -.45

Or count all values of the 12 presented that lie between 7.55 and 8.55

Answer = E
Should be 7.65 and not 7.55
8.1-0.45 = 7.65
Thanks for the edit DD.
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