372 is the answer.
(9*6*3)+(10*7*3)=372
Every confidence interval has associated z value. As confidence interval increases so do the z value associated with it.
The confidence interval can be calculated using following formula:

Where

is the mean value, z is the associated z value, s is the standard deviation and n is the number of samples.
We know that standard deviation is simply a square root of variance:

The confidence interval of 95% has associated z value of <span>1.960.
</span>Now we can calculate the confidence interval for our income:
Answer:
120 baseball cards
Step-by-step explanation:
15 × 2 = 30
30 + 10 = 40
40 ÷ 1/3 = 40 × 3/1 = 120
Therefore there were 120 cards in the back
<em>I just did the inverse of each process starting from the last step and ending at the first</em>
Answer:
no
Step-by-step explanation:
2 boxes of eggs = 1.30 × 2 = 2.60
1 bottle of juice = 2.60
he payed 10 and got 0.90 so he payed 9.10
9.10-2.60-2.60= 3.90 which is the price of the 3 baguettes so.... 3.90÷3= 1.30£ is the price for 1 baguette
Cramer's rule works as follows:
x+3y=16
3x+y=8
Then
x=Dx/D
y=Dy/D
where Dx,Dy,D are 2x2 matrices formed from of coefficients and right hand side.
D=
1 3
3 1
=1-9=-8
Dx=matrix D with first column replaced by the vector [16,8]=
16,3
8 1
=16-24
=-8
Dy=matrix D with second column replaced by the vector [16,8]=
1 16
3 8
=8-48
=-40
Therefore
x=-8/-8=1
y=--40/-8=5
Check:
x+3y=1+3(5)=16
3x+y=3(1)+5=8 ok.