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2 years ago

Help me out !!!!!!!!!!

Mathematics

1 answer:

SVETLANKA909090 [29]2 years ago

6 0

Answer:

Is it too late to tell you its 90 degrees

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

Please help!? Work out the size of angle x. 42 degrees and 123 degrees?

vlabodo [156]

Answer:

Sorry I don´t know the answer but I tried

Step-by-step explanation:

5 0

2 years ago

Read 2 more answers

Four brothers and their sister have the average age 7. Four brothers have the average age 6. How old is the sister?

AnnyKZ [126]

Answer:

11 years old

Step-by-step explanation:

If four brothers have the average age 6, then the sum of their ages is

$4\cdot 6=24$

years.

Let x years be the age of sister. If four brothers and their sister have the average age 7, then

$\dfrac{24+x}{5}=7.$

Multiply this equation by 5:

$24+x=35\Rightarrow x=35-24=11.$

The sister is 11 years old.

4 0

3 years ago

If the circumference of a circle measures 5 pie cm, what is the area of the circle in terms of pie?

saw5 [17]

Answer:

6.25π cm²

Step-by-step explanation:

pi = π

Circumference = 5πcm

Now first we should find radius(r)

2πr = 5π cm

pie will be cancelled and we get here

r = 5/ 2 cm

Therefore r = 2.5 cm

Now

Area (A) = πr²

= π * 2.5²

= 6.25π cm²

4 0

2 years ago

A recipe calls for 2 cups of flour to make 24 cookies. write and solve a proportion to find how much flour is needed to make 54

bekas [8.4K]

2 cups of flour x cups of flour
–––––––––––– = –––––––––––––
24 cookies 54 cookies

cross multiply
2*54=24x
24x=108
x=4.5

4.5 cups of flour

8 0

2 years ago