All categories

3 years ago

29.25 + 709-1)

Mathematics

1 answer:

aivan3 [116]3 years ago

8 0

Answer:

I not too sure if this is correct but your answer would be 737.25

You might be interested in

Please help! I will give brainlest answer

Sidana [21]

Connect the bdc letters together.

8 0

3 years ago

Read 2 more answers

Hannah buys 3 packs of 36 exposure film and 2 packs of 24 exposure film.She uses 8 rolls of film .How many rolls does she have l

stira [4]

She has 148 rolls left

3 0

3 years ago

Read 2 more answers

Which equation represents the graphed function?

CaHeK987 [17]

I think it would be y= -1/3+3

5 0

3 years ago

Read 2 more answers

Assume that the helium porosity of coal samples taken from any particular seam is Normally distributed with true standard deviat

riadik2000 [5.3K]

Answer:

a) $4.85-2.33\frac{0.75}{\sqrt{20}}=4.46$

$4.85+2.33\frac{0.75}{\sqrt{20}}=5.24$

b) $4.56-2.33\frac{0.75}{\sqrt{16}}=4.12$

$4.56+2.33\frac{0.75}{\sqrt{16}}=4.99$

c) $n=(\frac{1.960(0.75)}{0.2})^2 =54.02 \approx 55$

Step-by-step explanation:

Part a

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

The Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.01,0,1)".And we see that $z_{\alpha/2}=2.33$

Now we have everything in order to replace into formula (1):

$4.85-2.33\frac{0.75}{\sqrt{20}}=4.46$

$4.85+2.33\frac{0.75}{\sqrt{20}}=5.24$

Part b

$4.56-2.33\frac{0.75}{\sqrt{16}}=4.12$

$4.56+2.33\frac{0.75}{\sqrt{16}}=4.99$

Part c

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =0.4/2 =0.2 we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

$n=(\frac{1.960(0.75)}{0.2})^2 =54.02 \approx 55$

5 0

3 years ago

Solve for S plz <br><br> 5/8 - 3/8s = 2- s

Alexxx [7]

The photo has the answer

4 0

2 years ago