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2 years ago

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On a particular production line, the likelihood that a light bulb is defective is 10%. seven light bulbs are randomly selected.

What is the probability that at most 4 of the light bulbs will be defective

1 answer:

amid [387]2 years ago

6 0

Answer:

0.9995

Step-by-step explanation:

10% = 0.10

1 - 0.10 = 0.9

n = number of light bulbs = 7

we calculate this using binomial distribution.

p(x) = nCx × p^x(1-p)^n-x

our question says at most 4 is defective

= (7C0 × 0.1⁰ × 0.9⁷) + (7C1 × 0.1¹ × 0.9⁶) + (7C2 × 0.1² × 0.9⁵) + (7C3 × 0.1³ × 0.9⁴) + (7C4 × 0.1⁴ × 0.9³)

= 0.478 + 0.372 + 0.1239 + 0.023 + 0.0026

= 0.9995

we have 0.9995 probability that at most 4 light bulbs are defective.

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Solve the following system by any method -8x-8y=0 -8x+2y=-20

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$\text{Linear Equation} = -8x-8y=0 , -8x+2y=-20$

$\text{Rewrite the linear equations above as a matrix}$

$\left[\begin{array}{ccc}8&-8&0\\-8&2&-20\\\end{array}\right]$

$\text{Apply to Row2 : Row2 + Row1}$

$\left[\begin{array}{ccc}8&-8&0\\-8&-6&-20\\\end{array}\right]$

$\text{ Simplify rows}$

$\left[\begin{array}{ccc}8&-8&0\\0&1&10/3\\\end{array}\right]$

$\text{Note: The matrix is now in echelon form.}$ $\text{The steps below are for back substitution.}$

$\text{Apply to Row1 : Row1 + 8 Row2}$

$\left[\begin{array}{ccc}8&0&80/30\\0&1&10/3\\\end{array}\right]$

$\text{ Simplify rows}$

$\left[\begin{array}{ccc}1&0&10/3\\0&1&10/3\\\end{array}\right]$

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2 years ago

According to the National Association of Colleges and Employers, the average starting salary for new college graduates in health

katen-ka-za [31]

Answer:

a) The probability that a new college graduate in business will earn a starting salary of at least $65,000 is P=0.22965 or 23%.

b) The probability that a new college graduate in health sciences will earn a starting salary of at least $65,000 is P=0.11123 or 11%.

c) The probability that a new college graduate in health sciences will earn a starting salary of less than $40,000 is P=0.14686 or 15%.

d) A new college graduate in business have to earn at least $77,133 in order to have a starting salary higher than 99% of all starting salaries of new college graduates in the health sciences.

Step-by-step explanation:

<em>a. What is the probability that a new college graduate in business will earn a starting salary of at least $65,000?</em>

For college graduates in business, the salary distributes normally with mean salary of $53,901 and standard deviation of $15,000.

To calculate the probability of earning at least $65,000, we can calculate the z-value:

$z=\frac{x-\mu}{\sigma} =\frac{65000-53901}{15000} =0.74$

The probability is then

$P(X>65,000)=P(z>0.74)=0.22965$

The probability that a new college graduate in business will earn a starting salary of at least $65,000 is P=0.22965 or 23%.

<em>b. What is the probability that a new college graduate in health sciences will earn a starting salary of at least $65,000?</em>

<em />

For college graduates in health sciences, the salary distributes normally with mean salary of $51,541 and standard deviation of $11,000.

To calculate the probability of earning at least $65,000, we can calculate the z-value:

$z=\frac{x-\mu}{\sigma} =\frac{65000-51541}{11000} =1.22$

The probability is then

$P(X>65,000)=P(z>1.22)=0.11123$

The probability that a new college graduate in health sciences will earn a starting salary of at least $65,000 is P=0.11123 or 11%.

<em>c. What is the probability that a new college graduate in health sciences will earn a starting salary less than $40,000?</em>

To calculate the probability of earning less than $40,000, we can calculate the z-value:

$z=\frac{x-\mu}{\sigma} =\frac{40000-51541}{11000} =-1.05$

The probability is then

$P(X$

The probability that a new college graduate in health sciences will earn a starting salary of less than $40,000 is P=0.14686 or 15%.

<em />

<em>d. How much would a new college graduate in business have to earn in order to have a starting salary higher than 99% of all starting salaries of new college graduates in the health sciences?</em>

The z-value for the 1% higher salaries (P>0.99) is z=2.3265.

The cut-off salary for this z-value can be calculated as:

$X=\mu+z*\sigma=51,541+2.3265*11,000=51,541+25,592=77,133$

A new college graduate in business have to earn at least $77,133 in order to have a starting salary higher than 99% of all starting salaries of new college graduates in the health sciences.

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The error made by taking Egypt as being further from the sea level is assuming that the sea level is at the beginning (left) of the number line.

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The given elevation of the lowest points in the six countries are;

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Sorting the above countries from the country with the lowest point below sea level to the country with the highest point above sea level gives;

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However, point -133 > -154, therefore, -154 < -133, the symbol < represents lesser (in this case 'lower') which indicates that China (point -154) is lower or further left from zero which is the sea level than Egypt (point -133).

The error is therefore mistaking the location of the sea level as being at the extreme left of the number line, rather than at the middle.

Learn more about the number line here:

brainly.com/question/4727909

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