Answer: 40 seconds. This is the equation graphed
This is the concept of trigonometry, the value of x will be calculated as follows;
sin theta=[opposite]/[hypotenuse]
theta=x
opposite=16 units
hypotenuse=21 units
thus;
sin x=16/21
hence;
x=arcsin(16/21)
x=49.63
x=50 (to the nearest degrees)
The formula for the sum of the squares of the deviations is
SS = s² (N -1)
We are given
SS = 316
N = 9
Substituting
316 = s² (9 - 1)
Solving for s
s = 6.28
The standard deviation is 6.28
Given :
Emily sells erasers for $2 per package and pencils for $5 per package. she sells 220 total packages and earns $695.
To Find :
The number of packages of erasers and pencils that were sold
.
Solution :
Let, number of erasers are x and pencils are y.
So, x + y = 220 ....1
Also, 2x + 5y = 695 ....2
Solving equation 1 and 2, we get :

x = 220 - 85 = 135
Therefore, the number of packages of erasers and pencils that were sold are 135 and 85 respectively.
Hence, this is the required solution.
Let full be f and gallons be g
23f-2g=12f
2g=23f-12f
2g=11f
g=5.5f
note 23f is when it is full and x is the number of gallons the container can hold.
g=5.5f
xg=23f
x=46÷11
∴x approximately is 4.9