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3 years ago

How to find an unknown angle in a quadrilateral

1 answer:

4 0

Subtract the sum of the angles from 180 degrees to get the missing angle. For example if a triangle in a quadrilateral had the angles of 30 and 50 degrees, you would have a third angle equal to 100 degrees (180 - 80 = 100).

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Plsssss help before it gets locked

ddd [48]

A. Is answer F

B. Could be E or F

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2 years ago

Read 2 more answers

A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at th

Valentin [98]

Answer:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12.8$

The sample deviation calculated $s=4.324 \approx 4.3$

$12.8-4.604\frac{4.324}{\sqrt{5}}=3.896$

$12.8+ 4.604\frac{4.324}{\sqrt{5}}=21.704$

So on this case the 99% confidence interval would be given by (3.896;21.704)

Step-by-step explanation:

Data: 10,9,20,13,12

Previous concepts

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".

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

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

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

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

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12.8$

The sample deviation calculated $s=4.324$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=5-1=4$

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,4)".And we see that $t_{\alpha/2}=4.604$

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

$12.8-4.604\frac{4.324}{\sqrt{5}}=3.896$

$12.8+ 4.604\frac{4.324}{\sqrt{5}}=21.704$

So on this case the 99% confidence interval would be given by (3.896;21.704)

6 0

3 years ago

The distance between 0 and a

m_a_m_a [10]

Answer:

|a|

Step-by-step explanation:

if a was negative, the distance would be -a or absolute value a ( can be written as |a| ).

if a was positive, distance would be a. can also be written as |a|

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2 years ago

Find x<br> Secant tangent angles <br><br> Helpppp

valentinak56 [21]

Answer:

x = 139

Step by Step Explanation:

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3 years ago

Accuracy vs precision

Naily [24]

Accuracy is how close a measured item is to the actual or true value and precision is how close the measured items are to being the same. So you could weight 5 apples. If each apple weights 2 lbs and you said that the 5 apples weight a total of 10lbs you are determining the precision. Precision is independent of accuracy. Accuracy would be if you put all 5 apples on the scale at one time and knew a exact amount.

7 0

2 years ago