Answer:
a) Hence the endpoints of a t-distribution with 5% beyond them in each tail if the sample has size n=12 is ± 1.796.
b) Hence the endpoints of a t-distribution with 1% beyond them in each tail if the sample has size n=20 is ± 2.539.
Step-by-step explanation:
Here the answer is given as follows,
Complete question is;
A 21 ft ladder is leaning against a tall wall with the foot of the ladder placed at 7 feet from the base of the wall and the angle of elevation is?
Answer:
θ = 70.5°
Step-by-step explanation:
The angle of elevation simply means the angle that the ladder makes with the ground. Let's call this angle θ.
I've attached a diagram showing the triangle made by this ladder and the wall.
From the attached diagram, we can see the triangle formed by the ladder and the wall.
We can find the angle of elevation θ from trigonometric ratios.
Thus;
7/21 = cos θ
cos θ = 0.3333
θ = cos^(-1) 0.3333
θ = 70.5°
We are given ratio nickel to zinc to copper = 2:7:9.
From this ratio we can see that <em>ratio of nickel to zinc is 2:7</em>.
Let us assume number of pounds of nickel have to be used to create alloy that contains 4.9 lb of zinc is x pounds.
So, we can setup a proportion as :
x : 4.9 = 2:7
Or

On cross multiplication, we get
7x= 4.9× 2
7x = 9.8
Dividing both sides by 7, we get
x = 1.4.
<h3>Therefore, 1.4 pounds of nickel have to be used to create alloy that contains 4.9 lb of zinc.</h3><h3 />
Answer:
V=(πr^2 x h)/3
lets use π as 3.14 cause I dont know what pi u using
3.14 x 4^2 x 15 = 753.6/3 = 251.2
If you're using π as your pi, than just replace 3.14 by π on calculator
Hope that answers your question