12-5x-4kx=y solve for x

An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed, with mean equ

kompoz [17]

Answer:

0.62% probability that a random sample of 16 bulbs will have an average life of less than 775 hours.

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $\frac{\sigma}{\sqrt{n}}$

Normal probability distribution.

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 800, \sigma = 40, n = 16, s = \frac{40}{\sqrt{16}} = 10$

Find the probability that a random sample of 16 bulbs will have an average life of less than 775 hours.

This probability is the pvalue of Z when $X = 775$ . So

$Z = \frac{X - \mu}{s}$

$Z = \frac{775 - 800}{10}$

$Z = -2.5$

$Z = -2.5$ has a pvalue of 0.0062. So there is a 0.62% probability that a random sample of 16 bulbs will have an average life of less than 775 hours.

5 0

2 years ago

You notice you are growing awfully fast lately. You have been growing at a rate of 3 inches per year. If you are 5 feet tall now

Cerrena [4.2K]

Answer:

4 years

Step-by-step explanation:

FYI this sounds like a personal problem

6 0

2 years ago

Andrea has a yard shaped like parallelogram ABCD. The garden area, parallelogram EFGB, has an area of 105 ft2004-05-02-04-00_fil

Lynna [10]

The area of a parallelogram is simply calculated using the formula:

A = b * h

Where,

b = length of the base = 45 ft

h = height which is perpendicular to the base = 21 ft

Using the formula, we calculate the total area of the yard.

A = b* h

A = 45 ft * 21 ft

A = 945 ft^2

Now we don’t want to sod the Garden area for the most obvious reason. The garden has an Area of 105 ft^2, we subtract this to the total area giving us,

Area to sod = 945 ft^2 – 105ft^2

Area to sod = 840 ft^2

5 0

2 years ago

A paper company needs to ship paper to a large printing business. The paper will be shipped in small boxes and large boxes. Each

Jobisdone [24]

Answer:

your... syllabus is different from mine....

Step-by-step explanation:

which class u study

5 0

2 years ago

Out of six computer chips, two are defective. If two chips are randomly chosen for testing (without replacement), compute the pr

Ratling [72]

Answer:

The probability that of the two chips selected both are defective is 0.1089.

Step-by-step explanation:

Let X = number of defective chips.

It is provided that there are 2 defective chips among 6 chips.

The probability of selecting a defective chip is:

$P(X)=p=\frac{2}{6}=0.33$

A sample of n = 2 chips are selected.

The random variable X follows a Binomial distribution with parameter n = 2 and p = 0.33.

The probability function of a Binomial distribution is:

$P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0, 1, 2, ...$

Compute the probability that of the two chips selected both are defective as follows:

$P(X=2)={2\choose 2}(0.33)^{2}(1-0.33)^{2-2}=1\times 0.1089\times 1=0.1089$

Thus, the probability that of the two chips selected both are defective is 0.1089.

The sample space of selecting two chips is:

S = (1, 2), (1, 3), (1, 4), (1, 5), (1, 6)

(2, 1), (2, 3), (2, 4), (2, 5), (2, 6)

(3, 1), (3, 2), (3, 4), (3, 5), (3, 6)

(4, 1), (4, 2), (4, 3), (4, 5), (4, 6)

(5, 1), (5, 2), (5, 3), (5, 4), (5, 6)

(6, 1), (6, 2), (6, 3), (6, 4), (6, 5)

3 0

2 years ago