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Question by Max: Probability. Please help!?
An injection molding process leaves an average of 1.3 defects per bumper. Let Y and Z be the next two bumpers produced. Use an appropriate prob. function to evaluate:
a.)P[Y=2]
b.)P[Y>=1]
c.)sqr(Var Y)
d.)P[Y+Z>=2]

The problem does NOT say that it follows a normal distribution. This is quite literally all it gives. I’m assuming that this problem has something to do with the probability of 2 independent factors–I’ve looked at the section they are from but can’t find a thing. There are solutions if you have a standard deviation, but there wasn’t one given so I don’t know how to go about these. I have a normal distribution approx. table but I’m not sure if I can use it, or even how in this situation.

Best answer:

Answer by M3
the poisson distribution will be appropriate here. the formula is

P[x] = e^-m * m^x / x!

qa
m = 1.3, x = 2
P[2] = e^-1.3 * 1.3^2 /2!
= .2303
————

qb
P[>=1] = 1 – P[0] = 1 – e^-1.3 * 1.3^0 /0!
= .7275
———–

qc
variance of a posson distribution = m
sqrt(variance Y) = sqrt(1.3)
= 1,14
———

qd
for [Y+Z] , m = 2.6
applying the formula,
P[>=2] = 1 – { P[0] + P[1] }
= 1 – { e^-2.6 + e^-2.6*2.6/1! }
= .7326
———–

What do you think? Answer below!

Question by Max: Probability help?!?!?
An injection molding process leaves an average of 1.3 defects per bumper. Let Y and Z be the next two bumpers produced. Use an appropriate prob. function to evaluate:
a.)P[Y=2]
b.)P[Y>=1]
c.)sqr(Var Y)
d.)P[Y+Z>=2]

Best answer:

Answer by efqy
You’re presumably meant to assume a Poisson distribution with parameter 1.3

[The definition of Y and Z are wrong, and if your teacher/lecturer/textbook actually put that (“Let Y and Z be the next two bumpers produced”) they should be ashamed .

Y and Z should be “the number of defects on the next two bumpers produced, respectively”. If Y and Z were the bumpers themselves, they would not take values like 2, because bumpers are not numbers.]

a) just substitute 2 into the Poisson probability function with parameter 1.3

b) This is 1-P(Y=0)

c) what’s the variance of a Poisson random variable?

d) What’s the distribution of the sum of two independent Poissons?

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Question by unicornev: I am 45, working on BA in Business, overqualified for most jobs, cannot perform some What do I do now?
I am working on a BA in Business, but due to an injury, the work I used to do ( purely physical labor as a set up/process technician in an injection molding facility) is unavailable. I am over qualified for Burger King, but have only old (1992/1993) office experience. Since I do not have a degree yet (and with no experience, it probably wouldn’t help), how do I get a new job?

Best answer:

Answer by reina_de_trebol
I made the transition from kitchen work to an office by going through a temp agency. I used Kelly Services. They will not only test your current office skills, but they offer computer based training to get you up to speed in the areas you need help in. They will continue to work with you until you reach a level that they can place you at and all of these testing and training services are done for free around your regular work schedule.

I would imagine that the computer skills required in your degree program have prepared you more than you realize and you will test well.

Good luck.

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Question by Josh S: what are some manufacturing process for HDPE?
I’ve been searching Google all day now and i can not find out some ways to manipulate HDPE into becoming a product.

I do have a feeling that it is probably blow Molding or injection Molding.

Best answer:

Answer by Rolan R
Right, you are.
Blow-molding.
Found it in wikipedia.

just a one-liner there:
http://en.wikipedia.org/wiki/Hdpe#Applications

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Question by jasmine: what is the process of manufacture for a boardgame?
i need to do an A3 page on how a boardgame is made in pass production.
I have:
– Pre press
– Manufacture
-Finishing
i know that finishing is things like special effects e.g embossing, foil blocking..
but can you help me elaborate on manufacture? what is made first? The injection molding? printing? vacuum forming? help!

Best answer:

Answer by Stacee Mckee
Idk try posting this question on that yahoo answers site.

Give your answer to this question below!

Question by Oliver: Why do tires have small extrusions?
Every tire I have seen has small, cylindrical extrusions all around the tire. They are located on the tread of the tire. Why are these here? Are they left over from the injection mold process or something?

Best answer:

Answer by Dennis
Yes.

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Question by radha k: please let me know the process of recycling of EVA waste produced from injection moulding machines. as i have
know detailed process of recycling of EVA waste.

Best answer:

Answer by odysseus1959
I don’t understand your question.

At Flexible Products Corp. we have started to sell(?) our vulcanized urethane waste/runners to a recycler.

Even if we just gave it them, its better than the land fill.

Give your answer to this question below!

Question by Gary: Is there an information source for temperature ratings of various PVC, plastic, etc. compounds?
This material will be used in an injection molding process to construct a product that will be placed in close proximity to the burners on a stove top, not on them.

Best answer:

Answer by PlasticsAnswers
This site has all of the data sheets of all of the plastic compounds:

http://www.professionalplastics.com/
Just search for the material you are looking for, and click on view data sheet.

Here is their PVC data sheet:
http://www.professionalplastics.com/professionalplastics/content/PVCType1Properties.doc

I hope this helps.

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Question by Alex: I want to know the basic principle of Injection moulding and its process.?

Best answer:

Answer by up all night
plastic or some resin is melted in a barrell and mixed via an auger. forming dies (whatever form you are molding) are at the end of the barrell. hydraulic or electric rams hold the forms in place and the mold is filled with melted compound.

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Question by Felix: What are the most commonly used plastic processes (injection moulding, blow moulding etc.)?
From all of the different plastic processes what are the more common ones and how much are they each used?

Best answer:

Answer by chor510
It really depends on what type of parts and materials you are talking about.

Thermoforming is very popular for a lot of consumer goods. You basically take a sheet of plastic and press a mold into it. An example is TV dinner trays.

Blow molding is very popular for bottles. You start out with a peg of plastic and blow air into it and fill out a mold.

Many of the harder and more perminant plastics are injection molded. You inject plastic into a steel mold and then pull it apart.

Another is FRP – fiberglass reinforced plastic. You see this a lot in tub surrounds and boats. You start with a layer of fiberlass and either spray on or inject plastic.

What do you think? Answer below!