Standard deviation question
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Hi everyone, Someone asked for help in statistics. However, I have not done too much Math and could not figure this one out: A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds. question: what percentage of customers are still being kept waiting too long? Any one care to solve and explain? :) Cheers! Pankaj /** I'm the one who's gonna have to die When it's time for me to die So let me live my life The way I want to - Jimi Hendrix */
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Hi everyone, Someone asked for help in statistics. However, I have not done too much Math and could not figure this one out: A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds. question: what percentage of customers are still being kept waiting too long? Any one care to solve and explain? :) Cheers! Pankaj /** I'm the one who's gonna have to die When it's time for me to die So let me live my life The way I want to - Jimi Hendrix */
68% lie within 1 standard deviation of the mean, leaving 32% outside. Half of that are above one standard deviation to the right. It's been a while, so I might be completely wrong. http://www.andrews.edu/~calkins/math/webtexts/stat06.htm[^]
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68% lie within 1 standard deviation of the mean, leaving 32% outside. Half of that are above one standard deviation to the right. It's been a while, so I might be completely wrong. http://www.andrews.edu/~calkins/math/webtexts/stat06.htm[^]
Looks correct to me but it has also been awhile for me and I can't seem to find my stat book. Brad Jennings
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Hi everyone, Someone asked for help in statistics. However, I have not done too much Math and could not figure this one out: A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds. question: what percentage of customers are still being kept waiting too long? Any one care to solve and explain? :) Cheers! Pankaj /** I'm the one who's gonna have to die When it's time for me to die So let me live my life The way I want to - Jimi Hendrix */
Have a look at this.[^] The numbers along the x axis are the standard deviations, you can vary them unsymetrically (top) and symetrically (bottom). The probability is shown at the top of the plot. For a std dev of +/- 1, the probability is .6826, or 68.26% Gary Kirkham A working Program is one that has only unobserved bugs He is no fool who gives what he cannot keep to gain what he cannot lose. - Jim Elliot Me blog, You read
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68% lie within 1 standard deviation of the mean, leaving 32% outside. Half of that are above one standard deviation to the right. It's been a while, so I might be completely wrong. http://www.andrews.edu/~calkins/math/webtexts/stat06.htm[^]
Looks right to me. I double checked in my stats books and it is 68% (well, 68.26% to be exact). So you're right; about 16% of callers are waiting too long. The only problem I see is that we're assuming a normal distribution (ie: a bell curve). If the distribution is bimodal, geometric, binomial, etc. then it's a completely different story. For all we know, most callers might have quick easy problems to solve, but only a small percentage have problems which take a long time to solve which if I remember right would be called a Poison distribution. I hope I'm remembering this stuff right, becauste it's been a while. Oh well! I'm probably overthinking it. ;P
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Hi everyone, Someone asked for help in statistics. However, I have not done too much Math and could not figure this one out: A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds. question: what percentage of customers are still being kept waiting too long? Any one care to solve and explain? :) Cheers! Pankaj /** I'm the one who's gonna have to die When it's time for me to die So let me live my life The way I want to - Jimi Hendrix */
The ones who call from outside of India. ;P Sorry, couldn't resist. Chris Meech I am Canadian. [heard in a local bar] Gently arching his fishing rod back he moves the tip forward in a gentle arch releasing the line.... kersplunk [Doug Goulden]
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Hi everyone, Someone asked for help in statistics. However, I have not done too much Math and could not figure this one out: A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds. question: what percentage of customers are still being kept waiting too long? Any one care to solve and explain? :) Cheers! Pankaj /** I'm the one who's gonna have to die When it's time for me to die So let me live my life The way I want to - Jimi Hendrix */
Standard deviation in Texas is any person who thinks of something other than a meal when they look at cattle. ------- sig starts "I've heard some drivers saying, 'We're going too fast here...'. If you're not here to race, go the hell home - don't come here and grumble about going too fast. Why don't you tie a kerosene rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt "...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
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The ones who call from outside of India. ;P Sorry, couldn't resist. Chris Meech I am Canadian. [heard in a local bar] Gently arching his fishing rod back he moves the tip forward in a gentle arch releasing the line.... kersplunk [Doug Goulden]
5!
This demographic will quite happily click on shiny things however:laugh:
Found on Bash.org [erno] hm. I've lost a machine.. literally _lost_. it responds to ping, it works completely, I just can't figure out where in my apartment it is.
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Looks right to me. I double checked in my stats books and it is 68% (well, 68.26% to be exact). So you're right; about 16% of callers are waiting too long. The only problem I see is that we're assuming a normal distribution (ie: a bell curve). If the distribution is bimodal, geometric, binomial, etc. then it's a completely different story. For all we know, most callers might have quick easy problems to solve, but only a small percentage have problems which take a long time to solve which if I remember right would be called a Poison distribution. I hope I'm remembering this stuff right, becauste it's been a while. Oh well! I'm probably overthinking it. ;P
Gaussian distribution. The tigress is here :-D
