Does anyone know the answer 10*2/3*9 please?

What is 13/143 as a unit fraction?

AysviL [449]

1/11
143 divided by 13 is 11.

5 0

3 years ago

Read 2 more answers

Pls help! evaluate the sine of the real number, pls give exact answers

solong [7]

Answer:

$-\frac{\sqrt2}{2} \\$ or exact is −0.70710678...

Step-by-step explanation:

Getting the point!

If we look at the unit circle and we find $-\frac{3\pi }{4}$ we see it is in the 3rd quadrant.
We know that all points in the 3rd quadrant have both negative x and negative y values.
We know that all radians with the base of 4 on the unit circle have the points of $(\frac{\sqrt{2}}{2} ,\frac{\sqrt{2}}{2})$
Because we are in the 3rd quadrant and both x and y are negative we know the point of $-\frac{3\pi }{4}$ is $(-\frac{\sqrt{2}}{2}, -\frac{\sqrt{2}}{2})$

Finding the sin!

Because we know that sin is asking us for the y value
We can just look at the point and find the y value!
the y value is $-\frac{\sqrt2}{2} \\$
Because this fraction does not need to be rationalized we are good!
Use a calculator to find the exact value and you get -0.70710678...
The final answer is $-\frac{\sqrt2}{2} \\$ or exact is −0.70710678...

Hope this helps!! Please mark Brainliest!

4 0

2 years ago

3. Because h= b/2 we know that b =

Veronika [31]

Answer:

2 × h

Step-by-step explanation:

h = b ÷ 2 (multiply both sides by 2)

2 × h = b ÷ 2 × 2

2 × h = b

b = 2 × h

8 0

3 years ago

The Weschler Intelligence Scale for Children (WISC) is an intelligence test designed for children between the ages of 6 and 16.

Ostrovityanka [42]

Answer:

a) $\bar X = 121.4$

b) $SE = \frac{\sigma}{\sqrt{n}}= \frac{15}{\sqrt{40}}=2.372$

c) $121.4-1.64\frac{15}{\sqrt{40}}=117.51$

$121.4+1.64\frac{15}{\sqrt{40}}=125.29$

Step-by-step explanation:

Data given: 126,111,141,96,123,115,116,113,127,114,122,116,104,126,126,132,139,111,143,121,119,107,154,125,120,135,142,132,94,103,143,115,132,107,118,105,101,135,94,153

Part a

For this case we can calculate the sample mean with the following formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And after replace we got:

$\bar X = 121.4$

Part b

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".

For this case we assume that the population deviation is $\sigma=15$ , we can calculate the standard error with this formula:

$SE = \frac{\sigma}{\sqrt{n}}= \frac{15}{\sqrt{40}}=2.372$

Part c

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

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

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$