All categories

3 years ago

Which stament is true

Mathematics

2 answers:

Yuliya22 [10]3 years ago

8 0

Answer:thank u

Step-by-step explanation:

yanalaym [24]3 years ago

4 0

Answer:

i think it A

Step-by-step explanation:

You might be interested in

Sarah took the advertising department from her company on a round trip to meet with a potential client. Including Sarah a total

Alona [7]

Well lets do the math

220 x 8 = 1760

1240 x 2 = 2480

2480 + 1760 = 4240

So we need 2 first class and 8 coach.

8 0

3 years ago

Student scores on exams given by a certain instructor have mean 74 and standard deviation 14. This instructor is about to give t

Lapatulllka [165]

Answer:

$P(\bar X >80)=P(Z>2.143)=1-P(z$

Step-by-step explanation:

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Let X the random variable that represent the Student scores on exams given by a certain instructor, we know that X have the following distribution:

$X \sim N(\mu=74, \sigma=14)$

The sampling distribution for the sample mean is given by:

$\bar X \sim N(\mu,\frac{\sigma}{\sqrt{n}})$

The deduction is explained below we have this:

$E(\bar X)= E(\sum_{i=1}^{n}\frac{x_i}{n})= \sum_{i=1}^n \frac{E(x_i)}{n}= \frac{n\mu}{n}=\mu$

$Var(\bar X)=Var(\sum_{i=1}^{n}\frac{x_i}{n})= \frac{1}{n^2}\sum_{i=1}^n Var(x_i)$

Since the variance for each individual observation is $Var(x_i)=\sigma^2$ then:

$Var(\bar X)=\frac{n \sigma^2}{n^2}=\frac{\sigma}{n}$

And then for this special case:

$\bar X \sim N(74,\frac{14}{\sqrt{25}}=2.8)$

We are interested on this probability:

$P(\bar X >80)$

And we have already found the probability distribution for the sample mean on part a. So on this case we can use the z score formula given by:

$z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

Applying this we have the following result:

$P(\bar X >80)=P(Z>\frac{80-74}{\frac{14}{\sqrt{25}}})=P(Z>2.143)$

And using the normal standard distribution, Excel or a calculator we find this:

$P(Z>2.143)=1-P(z$

6 0

4 years ago

Place these numbers in correct order and and simplify 25x^2 +6x^3 -7 +17 -24x^4 +6

Ket [755]

Answer:

$-24x^4+6x^3+25x^2+16$

Step 1:

We need to place the numbers in descending order of the power. Here, $-24x^4$ has the largest power, so that number goes first. We keep doing this until we end up with our final expression, placed in order based on the powers.