2x - 6 = 0 and 2y = 10. Find 3^x/3^y.

How do you sketch the angle in standard position and 40 degrees

katen-ka-za [31]

A 40 degree angle: go from the right positive side of the x-axis and go left (left is positive degrees) forty degrees, which is a little less than halfway in quadrant 1.

8 0

2 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

2 years ago

Factor the equation: 25x^2-5xy-5xy^2+y^3-y^2

lianna [129]

Answer:

−5xy^2+y^3+25x^2−5xy−y^2

Step-by-step explanation:

25x^2−5xy−5xy^2+y^3−y^2=

25x^2−5xy−2

———————————-

7 0

2 years ago

What distance will a car traveling at a speed of 30m/s cover in 60 s?

AnnZ [28]

Answer:

1800 m/s if I'm not mistaken! :))

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

The ratio of chairs to tables in a classroom is 5:1 Which statement must be true? A There are 5 chairs and 1 table. B There are

qaws [65]

Answer:

B

Step-by-step explanation

5:1 means for every 1 table their is 5 chairs.

And for every 5 chairs there is 1 table.

8 0

2 years ago