20 POINTS

Find the area of ABC with the side lengths a=8 and b= 12, and the included angle C =84 degrees. Round your answer to the nearest

spin [16.1K]

Answer:

47.7 square units

Step-by-step explanation:

The area of triangle ABC with two given sides and an inclusive angle =

1/2absinC

Where : a = 8, b = 12, C = 84

Area of Triangle ABC = 1/2 × 8 × 12 × sin 84

Area of Triangle ABC = 47.737050978 square units

Approximately to the nearest tenth = 47.7 square units.

6 0

3 years ago

Is (x+7) a factor of f(x)= x^3-3x^2+2x-8

nikklg [1K]

Answer:

Step-by-step explanation:

Use synthetic division to answer this. If the remainder is zero, then we can safely assume the divisor (x + 7) is a factor of the polynomial f(x)= x^3-3x^2+2x-8.

We use -7 as the divisor in synth. div. This comes from the factor (x + 7):

-7 / 1 3 2 -8

-7 28 -210

-------------------------

1 -4 30 -218

Here, the remainder is -218, not zero, so no, (x+7) is not a factor of f(x)= x^3-3x^2+2x-8.

6 0

4 years ago

3u+5u=64<br> What is the simplify of this <br> What does u

Nutka1998 [239]

Answer:

u = 8

Step-by-step explanation:

3u + 5u = 64

8u = 64

8u/8 = 64/8

u = 8

8 0

4 years ago

As part of the Pew Internet and American Life Project, researchers conducted two surveys in late 2009. The first survey asked a

REY [17]

Answer:

The 95% confidence interval for the difference between the proportion of all U.S. teens and adults who use social networking sites is (0.223, 0.297). This means that we are 95% sure that the true difference of the proportion is in this interval, between 0.223 and 0.297.

Step-by-step explanation:

Before building the confidence interval we need to understand the central limit theorem and the subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

Sample of 800 teens. 73% said that they use social networking sites.

This means that:

$p_T = 0.73, s_T = \sqrt{\frac{0.73*0.27}{800}} = 0.0157$

Sample of 2253 adults. 47% said that they use social networking sites.

This means that:

$p_A = 0.47,s_A = \sqrt{\frac{0.47*0.53}{2253}} = 0.0105$

Distribution of the difference:

$p = p_T - p_A = 0.73 - 0.47 = 0.26$

$s = \sqrt{s_T^2+s_A^2} = \sqrt{0.0157^2+0.0105^2} = 0.019$

Confidence interval:

Is given by:

$p \pm zs$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

Lower bound:

$p - 1.96s = 0.26 - 1.96*0.019 = 0.223$

Upper bound:

$p + 1.96s = 0.26 + 1.96*0.019 = 0.297$

The 95% confidence interval for the difference between the proportion of all U.S. teens and adults who use social networking sites is (0.223, 0.297). This means that we are 95% sure that the true difference of the proportion is in this interval, between 0.223 and 0.297.

3 0

3 years ago

Complete the remainder of the table for the given function rule: y= x/4 + 7

babymother [125]

Let's replace x with -4 and simplify

y = (x/4) + 7

y = (-4/4) + 7

y = -1 + 7

y = 6

This means x = -4 and y = 6 pair up together.

So 6 goes in the box under the -4

----------------------------------------------------------

Repeat those steps for x = 0

y = (x/4) + 7

y = (0/4) + 7

y = 0 + 7

y = 7

So 7 goes in the box under the 0

----------------------------------------------------------

Let's repeat those steps for x = 4

y = (x/4) + 7

y = (4/4) + 7

y = 1 + 7

y = 8

So 8 goes in the box under the 4

----------------------------------------------------------

Lastly, for x = 8, we get

y = (x/4) + 7

y = (8/4) + 7

y = 2 + 7

y = 9

9 goes in the box under the 8

----------------------------------------------------------

The y outputs we got were: 6, 7, 8, 9

Notice how each time y increases by 1, x goes up by 4.

This means slope = rise/run = 1/4

We can think of x/4 as (1/4)x to help see that the slope is 1/4.

6 0

3 years ago