Where does the graph of y=-0.5x -2 cross the x-axis

Elden [556K]

Answer:

option A is correct !

hope this answer helps you dear...take care!

5 0

3 years ago

What is the reciprocal of 3 1/5

Talja [164]

Answer:

5/16

Step-by-step explanation:

We need to change the mixed number to an improper fraction to find the reciprocal

3 1/5 = (5*3+1)/5 = 16/5

The reciprocal of 16/5 is found by flipping the fraction

5/16

4 0

3 years ago

Read 2 more answers

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

Select the correct answer from each drop-down menu.

gavmur [86]

The summary of the ruler placement postulate is given as:

there is a one-to-one correspondence between the set of points on the line and the set of real numbers, and.
the distance between two points equals the absolute value of the difference between the corresponding numbers.

<h3>What is the ruler placement postulate?</h3>

This states that the points of a line can be matched and correspond to a set of points on the line and the set of real numbers,

Therefore, based on the fact that your question is incomplete, a general overview of the ruler placement postulate is given to give you a better understanding of the concept.

Read more about the ruler placement postulate here:

brainly.com/question/25097538

#SPJ1

4 0

2 years ago

An ice cream truck was parked near a beach, and some kids ran to it and formed a line. Then, more kids joined the line by fillin

Irina-Kira [14]

Answer:

7

Step-by-step explanation:

So, we know that this process happened 3 times in total. The original amount of kids we can call x, so the next wave filled in the gaps inbetween, so we call that amount x-1, the next wave would be (x+x-1)-1 or 2x-2, and the last would be 4x-4

adding this all up we get 8x-7=49, so 8x = 56 or x = 7

3 0

3 years ago