What is the length of a diagonal of a square with a side of 8

Please help!! Need an explanation by tomorrow and I am super confused!

vovangra [49]

Answer:

x = 35

y = 7

Step-by-step explanation:

See how the image looks like two overlapping triangles. It is given that the triangles are congruent. Its easier to see whats what if you draw the triangles separately. I also flipped over the triangle on the right so they match. Record the given angle measures. Since A is 45° then D is also 45°. DBC is 30°, so we can find the missing angle in triangle DBC. Angles in a triangle add up to 180° so

C + 45 + 30 = 180

C + 75 = 180

C = 105°

This is angle DCB.

Now all the angles are marked. We can set up equations to find x and y. see image.

7 0

2 years ago

Suppose that the researchers wanted to estimate the mean reaction time to within 6 msec with 95% confidence. Using the sample st

Lisa [10]

Answer:

a) The 95% confidence interval would be given by (509.592;550.308)

b) n=523 rounded up to the nearest integer

Step-by-step explanation:

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

$\bar X=530$ represent the sample mean for the sample

$\mu$ population mean

s=70 represent the sample standard deviation

n=48 represent the sample size (variable of interest)

Confidence =95% or 0.995

Part a

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

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

The degrees of freedom are df=n-1=48-1=47

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,47)".And we see that $z_{\alpha/2}=2.01$

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

$530-2.01\frac{70}{\sqrt{48}}=509.692$

$530+2.01\frac{70}{\sqrt{48}}=550.308$

So on this case the 95% confidence interval would be given by (509.592;550.308)

Part b

The margin of error is given by this formula:

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

Assuming that $\hat \sigma =s$

And on this case we have that ME =6msec, and 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 is provided, $z_{\alpha/2}=1.96$ , replacing into formula (b) we got:

$n=(\frac{1.96(70)}{6})^2 =522.88 \approx 523$

So the answer for this case would be n=523 rounded up to the nearest integer

3 0

3 years ago

What is the sqaure root of 40?

Kobotan [32]

Answer:

6.32455532034 or just 6

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Use set builder notation to give a description of each of these sets. a) {0,3,6,9,12} b) {−3,−2,−1,0,1,2,3} c) {m,n,o,p}

attashe74 [19]

Answer:

$\left \{ 0,3,6,9,12 \right \}=\left \{ x;x=3n\,,\,n\,\varepsilon \,W ;\,\,n\leq 4\right \}\\\left \{ -3,-2,-1,0,1,2,3 \right \}=\left \{ x;x=\pm n;\,\,n=0,1,2,3 \right \}\\\left \{ m,n,o,p \right \}=\left \{ x;x \,\,is\,\,an\,\,alphabet\,\,after\,\,l\,\,and\,\,before\,\,q \right \}$