Variance is equal to the square root of standard deviation. question 3 options:

A College Alcohol Study has interviewed random samples of students at four-year colleges. In the most recent study, 494 of 1000

Vinil7 [7]

Answer:

The 95% confidence interval for the difference between the proportion of women who drink alcohol and the proportion of men who drink alcohol is (-0.102, -0.014) or (-10.2%, -1.4%).

Step-by-step explanation:

We want to calculate the bounds of a 95% confidence interval of the difference between proportions.

For a 95% CI, the critical value for z is z=1.96.

The sample 1 (women), of size n1=1000 has a proportion of p1=0.494.

$p_1=X_1/n_1=494/1000=0.494$

The sample 2 (men), of size n2=1000 has a proportion of p2=0.552.

$p_2=X_2/n_2=552/1000=0.552$

The difference between proportions is (p1-p2)=-0.058.

$p_d=p_1-p_2=0.494-0.552=-0.058$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{494+552}{1000+1000}=\dfrac{1046}{2000}=0.523$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.523*0.477}{1000}+\dfrac{0.523*0.477}{1000}}\\\\\\s_{p1-p2}=\sqrt{0.000249+0.000249}=\sqrt{0.000499}=0.022$

Then, the margin of error is:

$MOE=z \cdot s_{p1-p2}=1.96\cdot 0.022=0.0438$

Then, the lower and upper bounds of the confidence interval are:

$LL=(p_1-p_2)-z\cdot s_{p1-p2} = -0.058-0.0438=-0.102\\\\UL=(p_1-p_2)+z\cdot s_{p1-p2}= -0.058+0.0438=-0.014$

The 95% confidence interval for the difference between proportions is (-0.102, -0.014).

7 0

2 years ago

A percent is a rate in which the first term is compared to ______

PIT_PIT [208]

Answer:

From what we know about percentages and unit rates, the correct options are:

1) 100

2) 1

What is a percent?

Suppose we have an amount A, this would be the 100%.

If we want to know how much a quantity B represents, compared to A, we have:

A = 100%

B = x

where x is a percentage, to find the value of x we compute:

x = (B/A)*100%

While there is a dependence on A, we actually are comparing the term with 100 (because A represents a 100%), so the correct option is A: 100

<u><em>PLS MARK ME AS THE BRAINLIST!!!</em></u>

6 0

2 years ago

Help me I need the answer to #2 and #4

Karo-lina-s [1.5K]

Number 2 is 84.13
number 4 is 56

3 0

2 years ago

Last year, 800 students attended the career fair at west high school. this year,the number of students who attended the career f

Delvig [45]

Answer:

840

Step-by-step explanation:

Last year, 800 students attended the career fair at West High School.

And, this year the number of students who attended the career fair increased by 5%.

We are asked how many students attended the career fair at West High School this year.

Therefore, the number of students attended the career fair at West High School will be $800[1+\frac{5}{100} ] =800 \times 1.05 = 840$ . (Answer)

3 0

2 years ago

The following graph describes function 1, and the equation below it describes function 2. Determine which function has a greater

LenaWriter [7]

Answer:

Function 1 has the larger maximum at (4, 1)

Explanation:

After observation, graph of function 1 has vertex at Maximum (4, 1)

In order to find vertex of function 2, complete square the equation.

f(x) = -x² + 2x - 3

f(x) = -(x² - 2x) - 3

f(x) = -(x - 1)² - 3 + (-1)²

f(x) = -(x - 1)² - 2

Vertex form: y = a(x - h)² + k where (h, k) is the vertex

So, here for function 2 vertex: Maximum (1, -2)

<h3>Conclusion:</h3>

Function 1 = Maximum (4, 1), Function 2 = Maximum (1, -2)

Function 1 has greater maximum value of (4, 1) as "1 is greater than -2"

5 0

1 year ago