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GMATT73
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:07
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A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?



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yuefei
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:12
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GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
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4/500 or 8/1000 = .8% or 800% increase in defectives. I hope they have an SLA agreement :)
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trivikram
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:15
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A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
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Not sure if this is what you are looking for

I would say its in the Mean + 1SD range ....

|-2.3%-|---13.6%---|----34.1%----M----34.1%----|---13.6%---|-2.3%-|

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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:17
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yuefei
GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?

4/500 or 8/1000 = .8% or 800% increase in defectives. I hope they have an SLA agreement :)
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yuefei, you need to use the mean and the SD to for binomial distribution to make the inference here.
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:23
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A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
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Based on the samples taken,
4/500 = 8/1000 = 0.8% are defective

This is 8 times the guaranteed number. Therefore, you can inter that the statement of guarantee is not accurate.
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GMATT73
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:23
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A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
Not sure if this is what you are looking for

I would say its in the Mean + 1SD range ....

|-2.3%-|---13.6%---|----34.1%----M----34.1%----|---13.6%---|-2.3%-|

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Close, but much more than 1SD here. :!:
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:28
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trivikram
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A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
Not sure if this is what you are looking for

I would say its in the Mean + 1SD range ....

|-2.3%-|---13.6%---|----34.1%----M----34.1%----|---13.6%---|-2.3%-|


Close, but much more than 1SD here. :!:
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Shoot ...shoot............Mean + 2SD
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:46
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trivikram
GMATT73
trivikram
GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
Not sure if this is what you are looking for

I would say its in the Mean + 1SD range ....

|-2.3%-|---13.6%---|----34.1%----M----34.1%----|---13.6%---|-2.3%-|


Close, but much more than 1SD here. :!:

Shoot ...shoot............Mean + 2SD
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(1) X = # of defective switches out of 500, where each switch has a .001 probability of being defective --> 500*.001 ---> .5

(2) SD of X = sqrt {500*.001*(1-.001)} ---> .7067

(3) The observation X=4 is (4-.5)/.7067 ---> 4.955 SD

Final answer, four defectives is a highly unlikely result !!! Take one more sample or send the switches back to the manufacturer.

(3SD is about 99.6%)
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trivikram
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 19:50
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trivikram
GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
Not sure if this is what you are looking for

I would say its in the Mean + 1SD range ....

|-2.3%-|---13.6%---|----34.1%----M----34.1%----|---13.6%---|-2.3%-|


Close, but much more than 1SD here. :!:

Shoot ...shoot............Mean + 2SD

(1) X = # of defective switches out of 500, where each switch has a .001 probability of being defective --> 500*.001 ---> .5

(2) SD of X = sqrt {500*.001*(1-.001)} ---> .7067

(3) The observation X=4 is (4-.5)/.7067 ---> 4.955 SD

Final answer, four defectives is a highly unlikely result !!! Take one more sample or send the switches back to the manufacturer.

(3SD is about 99.6%)
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OK I give up :-)
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A company has purchased 50K electrical switches and has been 22 Oct 2007, 21:56
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GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
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Not to trust this supplier.
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ywilfred
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A company has purchased 50K electrical switches and has been 23 Oct 2007, 02:16
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inference: I won't be getting my switches from this company.
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A company has purchased 50K electrical switches and has been 03 Nov 2007, 13:11
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You guys ready for a few more of these problems?
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Pzazz
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A company has purchased 50K electrical switches and has been 03 Nov 2007, 13:30
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apart from these 500 the rest contains less number of defected switches..since these have been picked up randomly....!!!!!!!!!!!
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GMAT TIGER
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A company has purchased 50K electrical switches and has been 03 Nov 2007, 13:47
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GMATT73
A company has purchased 50K electrical switches and has been guaranteed by the supplier that the shipment will contain no more than .1% defectives. A random sample of 500 switches are tested and 4 are defective. Based on this sample, what inference would you make about the suppliers guarantee?
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definitely the immidiate impression is not good but its not enough to reach at any conclusion. we cannot say anything cuz we do not know the sample is normally distributed.



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Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
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