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2 years ago

15

Someone please help????

1 answer:

Nonamiya [84]2 years ago

7 0

Answer:

p is 13

Step-by-step explanation:

You might be interested in

A simple random sample of size nequals81 is obtained from a population with mu equals 83 and sigma equals 27. (a) Describe the

Ivanshal [37]

Answer:

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

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

b) $z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

c) $z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

d) $z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

Step-by-step explanation:

For this case we know the following propoertis for the random variable X

$\mu = 83, \sigma = 27$

We select a sample size of n = 81

Part a

Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

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

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

Part b

We want this probability:

$P(\bar X>89)$

We can use the z score formula given by:

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

And if we find the z score for 89 we got:

$z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

Part c

$P(\bar X$

We can use the z score formula given by:

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

And if we find the z score for 75.65 we got:

$z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

Part d

We want this probability:

$P(79.4 < \bar X < 89.3)$

We find the z scores:

$z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

8 0

3 years ago

A mathematical term that does not include an equal or inequality sign is called an

Evgen [1.6K]

The answer would be a mathematical phrase. Hope that helped.

3 0

3 years ago

What was the rate of change between $73 and $74 <br><br> Please help

kari74 [83]

Answer:1

Step-by-step explanation:

6 0

2 years ago

NEED ANSWER ASAP PLEASE WILL GIVE BRAINLIEST An integer n is divided by 2 and the quotient is an even integer. What does this te

Nesterboy [21]

Answer:

$n$ is a multiple of 4

Step-by-step explanation:

Let's think about this.

Even numbers are basically numbers that, when divided by 2, get us an integer.

This means that $n$ must be an even integer.

<em>However,</em>

Every other even number, when divided by 2, gets you an odd integer.

This means that every second even number, $n \div 2$ gets us an even number.

This also means that every time $n \div 2$ is an even number, n will be a multiple of 4 (as $2\cdot 2 = 4$ ).

Test this out with any even number that's a multiple of 4 (all multiples of 4 are even numbers)

Hope this helped!

4 0

3 years ago

A N S W E R Q U I C K P L E A S E

chubhunter [2.5K]

Answer:

1. A

2. D

3. D

Step-by-step explanation:

The standard form of a parabola is

$y=\frac{1}{4p}(x-h)^2+k$ ..... (1)

Where, (h,k) is vertex, (h,k+p) is focus and y=k-p is directrix.

1. The directrix of a parabola is y=−8 . The focus of the parabola is (−2,−6) .

$k-p=-8$ ...(a)

$(h,k+p)=(-2,-6)$

$k+p=-6$ .... (b)

$h=-2$

On solving (a) and (b), we get k=-7 and p=1.

Put h=-2, k=-7 and p=1 in equation (1).

$y=\frac{1}{4(1)}(x-(-2))^2+(-7)$

$y=\frac{1}{4}(x+2)^2-7$

Therefore option A is correct.

2 The directrix of a parabola is the line y=5 . The focus of the parabola is (2,1) .

$k-p=5$ ...(c)

$(h,k+p)=(2,1)$

$k+p=1$ .... (d)

$h=2$

On solving (c) and (d), we get k=3 and p=-2.

Put h=2, k=3 and p=-2 in equation (1).

$y=\frac{1}{4(-2)}(x-(2))^2+(3)$

$y=-\frac{1}{8}(x-2)^2+3$

Therefore option D is correct.

3. The focus of a parabola is (0,−2) . The directrix of the parabola is the line y=−3 .

$k-p=-3$ ...(e)

$(h,k+p)=(0,-2)$

$k+p=-2$ .... (f)

$h=0$

On solving (e) and (f), we get k=-2.5 and p=0.5.

Put h=0, k=-2.5 and p=0.5 in equation (1).

$y=\frac{1}{4(0.5)}(x-(0))^2+(-2.5)$

$y=\frac{1}{2}(x)^2-2.5$

$y=\frac{1}{2}(x)^2-\frac{5}{2}$

Therefore option D is correct.

5 0

2 years ago