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3 years ago

What is a artafart and a Earth quack?

1 answer:

3 0

Aftershocks occur after the most major part of an earth quake happens. Earthquakes occur at fault lines near the tectonic border. They occur because of the sudden movement for staying rigid while they were edging closer and closer. So the sudden movement releases a large amount of tension buried deep below the earth creating or resulting in an earthquake.

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What does 14x - 200y = when x = 12 and y = 3.2?

myrzilka [38]

14(12)-200(3.2)
168-640= -472

5 0

2 years ago

Read 2 more answers

Simplify 2(-3×4)-10

maks197457 [2]

The answer is -34

Explication

2✖️(-12)-10
-24-10
-34

7 0

3 years ago

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A quality control expert at LIFE batteries wants to test their new batteries. The design engineer claims they have a variance of

iris [78.8K]

Answer:

The probability that the mean battery life would be greater than 533.2 minutes (in a sample of 75 batteries) is $\\ P(z>0.48) = P(x>533.2) = 0.3156$

Step-by-step explanation:

The main thing we have to take into account in this question is that we are about to find the probability of a sample mean. The distribution for sample means follows a normal distribution with mean $\\ \mu$ and standard deviation $\\ \frac{\sigma}{\sqrt{n}}$ . Mathematically

$\\ \overline{x} \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

For values of the sample $\\ n \ge 30$ , no matter the distribution the data come from.

And the variable z follows a standard normal distribution, and, as we can remember, this distribution has a mean = 0 and a standard deviation = 1. Mathematically

$\\ z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$ [1]

That is

$\\ z \sim N(0, 1)$

We have a variance of 3364. That is, a standard deviation of

$\\ \sigma^2 = 3364; \sigma = \sqrt{3364} = 58$

The population mean is

$\\ \mu = 530$

The sample size is $\\ n = 75$

The sample mean is $\\ \overline{x} = 533.2$

With all this information, we can solve the question

The probability that the mean battery life would be greater than 533.2 minutes

Using equation [1]

$\\ z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$\\ z = \frac{533.2 - 530}{\frac{58}{\sqrt{75}}}$

$\\ z = \frac{3.2}{\frac{58}{8.66025}}$

$\\ z = \frac{3.2}{6.69726}$

$\\ z = 0.47780$

With this value of z we can consult a cumulative standard normal table (or use some statistic program) to find the cumulative probability for z (and remember that this variable follows a standard normal distribution).

Most standard normal tables have values for z for only two decimals, so we can round the previous value for z as z = 0.48.

Then

$\\ P(z$

However, in the question we are asked for $\\ P(z>0.48) = P(x>533.2)$ . As well as all normal distributions, the standard normal distribution is symmetrical around the mean, and we have

$\\ P(z>0.48) = 1 - P(z$

Thus

$\\ P(z>0.48) = 1 - 0.68439$

$\\ P(z>0.48) = 0.31561$

Rounding to four decimal places, we have

$\\ P(z>0.48) = 0.3156$

So, the probability that the mean battery life would be greater than 533.2 minutes is (in a sample of 75 batteries) $\\ P(z>0.48) = P(x>533.2) = 0.3156$ .

5 0

3 years ago

What is the value of x in the figure below?

astraxan [27]

Step-by-step explanation:

85 degrees ok get your homework done now

4 0

3 years ago

What is the sum of the measures of the interior angles of this heptagon? A 7-sided figure. 720 degrees 900 degrees 1,080 degrees

NeTakaya

Answer:

900°

Step-by-step explanation:

interior angles of a polygon = (n−2)×180°, where n is number of sides

for heptagon it is: (7-2)×180°= 900°

8 0

3 years ago

Read 2 more answers