Answer:
x=14
Step-by-step explanation:
9x = 3x + 84
9x-3x=84
6x=84
x=84/6
x=14
Answer:
x=2
Step-by-step explanation:
Answer:
x = 4 and y = 8
Step-by-step explanation:
This is a special right triangle with angle measures 90-60-30 degrees
The side lengths are like the following :
The side length that sees 90 degrees is represented with a
The side length that sees 60 degrees is represented with a
The side length that sees 30 degrees is represented with 2a
now, the angle measure that sees 60 degrees is given as 4
so we understand that a is = 4 that's how we find the value of x and y
The confidence interval is

. This means that we can be 99% confident that the mean number of books people read lies between 9.15 and 11.85.
To find the confidence interval, we first find the z-score associated with it:
Convert 99% to a decimal: 0.99
Subtract from 1: 1-0.99=0.01
Divide by 2: 0.01/2 = 0.005
Subtract from 1: 1-0.005 = 0.995
Using a z-table (http://www.z-table.com) we see that this is associated with a z-score between 2.57 and 2.58. Since both are equally far from this value we will use 2.575.
We calculate the margin of error using

This means that the confidence interval is

The lower limit is given by 10.5-1.35 = 9.15.
The upper limit is given by 10.5+1.35 = 11.85
Answer:
This problem is a great systems of equations problem--you have two different variables: song size and number of songs.
Let's call the number of standard version downloads (S) and the high quality downloads (H).
You can make two statements:
For number of songs downloaded: S + H = 910
For download size: 2.8(S) + 4.4(H) = 3044.
S will be the same number in both equations and H will be the same number in both equations, so to find S, we can rearrange the first statement to H = 910 - S, then substitute or plug in (910 - S) wherever you see an H in the second equation so that you have only S's in your equation. Should look like this:
2.8(S) + 4.4(910 - S) = 3044
2.8S + 4004 - 4.4S = 3044
-1.6S = -960
s = 600
Your question only asks for the standard version downloads, but to help you out in future Systems situations-
You can also solve for H once you have S by plugging it into either of your equations like this:
600 + H = 910
-600
H=310
Step-by-step explanation:
hope it help
*comment if my answer is wrong*