Ask question

Ask question

All categories

3 years ago

9

You want to estimate the mean amount of time college students spend on the Internet each month. How many college students must y

ou survey to be 95% confident that your sample mean

1 answer:

KonstantinChe [14]3 years ago

8 0

Answer:

752.95

Step-by-step explanation:

Data provided in the question

The standard deviation of population = 210

The Margin of error = 15

The confidence level is 75%, so the z value is 1.96

Now the required sample size is

$= 1.96^2\times \frac{210^2}{15^2}$

= 752.95

Hence, the number of college students spends on the internet each month is 752.95

Simply we considered the above values so that the n could come

You might be interested in

Two collinear points on a line are given in the table below:

katrin [286]

Answer:

$(4,3)$ and $(7,2)$ do not lie on the line

Step-by-step explanation:

Given

$(0,0)\ and\ (2,1)$

Required

Determine which points that are not on the line

First, we need to determine the slope (m) of the line:

$m = \frac{y_2 - y_1}{x_2- x_1}$

Where

$(x_1,y_1) = (0,0)$

$(x_2,y_2) = (2,1)$

So;

$m = \frac{y_2 - y_1}{x_2- x_1}$

$m = \frac{1 - 0}{2-0}$

$m = \frac{1}{2}$

Next, we determine the line equation using:

$y - y_1 = m(x -x_1)$

Where

$m = \frac{1}{2}$

$(x_1,y_1) = (0,0)$

$y - y_1 = m(x -x_1)$ becomes

$y - 0 = \frac{1}{2}(x - 0)$

$y = \frac{1}{2}x$

To determine which point is on the line, we simply plug in the values of x to in the equation check.

For $(4,2)$

$x = 4$ and $y =2$

Substitute 4 for x and 2 for y in $y = \frac{1}{2}x$

$2 = \frac{1}{2} * 4$

$2 = \frac{4}{2}$

$2=2$

<em>This point is on the graph</em>

<em></em>

For $(4,3)$

$x = 4$ and $y = 3$

Substitute 4 for x and 3 for y in $y = \frac{1}{2}x$

$3 = \frac{1}{2} * 4$

$3 = \frac{4}{2}$

$3 \neq 2$

<em>This point is not on the graph</em>

<em></em>

For $(7,2)$

$x = 7$ and $y = 2$

Substitute 7 for x and 2 for y in $y = \frac{1}{2}x$

$2 = \frac{1}{2} * 7$

$2 = \frac{7}{2}$

$2 \neq 3.5$

<em></em>

<em>This point is not on the graph</em>

<em></em>

<em></em> $(\frac{4}{8},\frac{2}{8})$ <em></em>

<em></em> $x = \frac{4}{8}$ and<em> </em> $y = \frac{2}{8}$ <em></em>

<em>Substitute </em> $\frac{4}{8}$ <em> for x and </em> $\frac{2}{8}$ <em> for y in </em> $y = \frac{1}{2}x$ <em></em>

<em></em> $\frac{2}{8} = \frac{1}{2} * \frac{4}{8}$ <em></em>

<em></em> $\frac{2}{8} = \frac{1 * 4}{8 * 2}$ <em></em>

<em></em> $\frac{2}{8} = \frac{4}{16}$ <em></em>

<em></em> $\frac{1}{4} = \frac{1}{4}$ <em></em>

<em></em>

<em>This point is on the graph</em>

3 0

3 years ago

Granola costs $6.50 per pound. Assorted nuts cost $9 per pound. How many pounds of granola and nuts are needed to make 9 pounds

bezimeni [28]

Answer:

3.6 pounds of granola and 5.4 pounds of nuts

Step-by-step explanation:

Let the required granola be x pounds, then amount of nuts is 9 - x.

<u>The price of the mixture is as below equation:</u>

6.5x + 9(9 - x) = 8*9
6.5x + 81 - 9x = 72
81 - 2.5x = 72
2.5x = 81 - 72
2.5x = 9
x = 9/2.5
x = 3.6

<u>Find the amount of nuts:</u>

9 - 3.6 = 5.4

7 0

2 years ago

What is a reasonable estimate for the problem? 3 3/4 x -2/5

Airida [17]

Answer:

You can not break that down any further if x does not equal anything and the equation is not equal to anything.

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

The equation below shows the relationship between the number of apples purchased, a, and the total cost

inessss [21]

Answer:

C

Step-by-step explanation:

a (5) = c (4)

5 x 4 = 20

20 (total) divided by the 5 apples is $4.

6 0

3 years ago

Read 2 more answers

A cell phone store sold 450 newly released cell phones in three hours. This was 30% of the number of cell phones sold that day.

Vitek1552 [10]

Answer:

we have 3 things here. 30% out of 100% of the 450 phones

In order to find the missing percent we multiply the 450 by 100 and divide its product by 30

The answer is 1500

Step-by-step explanation:

8 0

3 years ago