Dell Computers receives large shipments of microprocessors (chips) from Intel Corp. It must try to ensure that the proportion of defective chips is small and has contracted to keep the proportion of defective chips at 5% or less. Suppose that Dell tests 25 chips (with replacement) out of a shipment of thousands.
a) What is the probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives? If a sample results in at least three defects, does it appear that Intel has provided a shipment which is consistent with the contract? Briefly explain, using the calculated probability.
b) For the shipment described in part a, find the expected number of sampled chips that are defective and the standard deviation of the number of sampled chips that are defective.
c) Suppose that 20% of the entire shipment is defective. What is the probability that more than 17 chips in the sample are good (not defective)?​

Using the binomial distribution, it is found that:

a) 0.1271 = 12.71% probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives. 5% defective is between 1 and 2 defects, but since this probability is more than the unlikely threshold 5%, more than 2 defects could still mean that Intel has provided a shipment which is consistent with the contract.

b) The mean is of 1.25 defective chips and the standard deviation is of 1.09 defective chips.

c) 0.8908 = 89.08% probability that more than 17 chips in the sample are good.

For each chip, there are only two possible outcomes, either it is defective, or it is not. The probability of a chip being defective is independent of any other chip, which means that the binomial distribution is used to solve this question.

Binomial probability distribution

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this problem:

Item a:

Supposing 5% defective, we have that [tex]p = 0.05[/tex].

The probability is:

[tex]P(X \geq 3) = 1 - P(X < 3)[/tex]

In which

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]

Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{25,0}.(0.05)^{0}.(0.95)^{25} = 0.2774[/tex]

[tex]P(X = 1) = C_{25,1}.(0.05)^{1}.(0.95)^{24} = 0.3650[/tex]

[tex]P(X = 2) = C_{25,2}.(0.05)^{2}.(0.95)^{23} = 0.2305[/tex]

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0.2774 + 0.3650 + 0.2305 = 0.8729[/tex]

[tex]P(X \geq 3) = 1 - P(X < 3) = 1 - 0.8729 = 0.1271[/tex]

0.1271 = 12.71% probability of obtaining at least three defects in the sample, if the entire shipment has 5% defectives. 5% defective is between 1 and 2 defects, but since this probability is more than the unlikely threshold 5%, more than 2 defects could still mean that Intel has provided a shipment which is consistent with the contract.

Item b:

The mean is:

[tex]E(X) = np = 25(0.05) = 1.25[/tex]

The standard deviation is:

[tex]\sqrt{V(X)} = \sqrt{np(1 - p)} = \sqrt{25(0.05)(0.95)} = 1.09[/tex]

The mean is of 1.25 defective chips and the standard deviation is of 1.09 defective chips.

Item c:

20% are defective, so 80% are good, which means that [tex]p = 0.8[/tex]

The probability is:

[tex]P(X > 17) = P(X = 18) + P(X = 19) + P(X = 20) + P(X = 21) + P(X = 22) + P(X = 23) + P(X = 24) + P(X = 25)[/tex]

Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 18) = C_{25,18}.(0.8)^{18}.(0.2)^{7} = 0.1108[/tex]

[tex]P(X = 19) = C_{25,19}.(0.8)^{19}.(0.2)^{6} = 0.1633[/tex]

[tex]P(X = 20) = C_{25,20}.(0.8)^{20}.(0.2)^{5} = 0.1960[/tex]

[tex]P(X = 21) = C_{25,21}.(0.8)^{21}.(0.2)^{4} = 0.1867[/tex]

[tex]P(X = 22) = C_{25,22}.(0.8)^{22}.(0.2)^{3} = 0.1358[/tex]

[tex]P(X = 23) = C_{25,23}.(0.8)^{23}.(0.2)^{2} = 0.0708[/tex]

[tex]P(X = 24) = C_{25,24}.(0.8)^{24}.(0.2)^{1} = 0.0236[/tex]

[tex]P(X = 25) = C_{25,25}.(0.8)^{25}.(0.2)^{0} = 0.0038[/tex]

Then:

[tex]P(X > 17) = P(X = 18) + P(X = 19) + P(X = 20) + P(X = 21) + P(X = 22) + P(X = 23) + P(X = 24) + P(X = 25) = 0.1108 + 0.1633 + 0.1960 + 0.1867 + 0.1358 + 0.0708 + 0.0236 + 0.0038 = 0.8908[/tex]

0.8908 = 89.08% probability that more than 17 chips in the sample are good.

A similar problem is given at https://brainly.com/question/24863377

When converted to a household measurement, 9 kilograms is approximately equal to a

HELP LAST ATTEMPT ??!!

I have more question then this one

If the interest earned is $96.00 at a rate of 4% for 6 years, how much principal was invested? step by step equation please ​

50 tickets need sold but only 9 have been sold what percent have been sold?

The hourly rate for a lecturer is £17.50. She works 35 hours a week and 8 hours overtime at time-and-a-half. What is her total pay for the week?​

In a circle L, M, N are the points on the circle forming a triangle with LM = LN and mZMLN is 35' then what is m(arc LN)?​

Find the Area of the figure below, composed of a parallelogram and one semicircle. Rounded to the nearest tenths place

Multiply 3hrs 30mins by 4

Adjoa’s gross salary for last month was Ghc4,687.24. If Ghc421.78 was deducted from Adjoa’s salary pay, how much take-home pay did Adjoa earn this past month?

You give an 18% tip for a meal. What expression represents the total cost with tip?

1/4×10/12 simplest form

Please answer #1 hurry!!! Will give brainliest

5n + 1/8 = 3n-5/4
Solve for n

someone please help with this question for brainliest !!!!:)

Last month, when Joe took his puppy to the veterinarian, the puppy weighed 6.7 pounds. This month, the puppy weighed 10.05 pounds. What is the percentage increase of the weight of the puppy?

.21 is what percent of $3.50

A true/false test has 20 questions on it. What is the probability that you get at least 18 right by purely guessing?

Pls help I’ll brainlest and add extra points

Given f(x) = 9-3x and g(x) = - 6x + 3, find (f + g)(x).

an example of an abelian group which is not cyclic

PLEASE HELP ITS MATH THANK YOUUUU

Entrance to a state park costs $6 per vehicle, plus $2 per person in the vehicle the cost for a bus with 50 people?

Julie bought 4,649 lemons to make lemonade for a birthday party if this number is rounded to the nearest hundred about how many lemons did Julie bought ?

I need the solving too please

​

Solve the equation for X x - 5 = 12​

Which equation describes the sum of the vectors plotted below?
6
A. r 38 27
B. 2x+y
C. r 38 1 27
O Dr 3x Ý

plot 1 1/2 and its opposite on the number line

HELPPPPPPPPPPPPPPPPPPPPPPPPPPP

What is the y-intercept of the line y =
= {x-5
-5?

Find the area of the circle.