Answer:
14
Step-by-step explanation:
Hypotenuse^2=base^2+perp^2
50^2=base^2+48^2
2500-2304=base^2
Base^2=196
Taking sq root
Base=14
<u>Answer</u>: No, we do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Step-by-step explanation:
As per given , we have
, since 
is two-tailed so , the test is a two tail test.
Since population standard deviation is unknown, so we use t-test.
Critical value (two-tailed) for significance level of 0.01= 
For n =50 , 
and s= 4.8
Test statistic : 
Since test statistic value (-1.18) lies in critical interval (-2.609228, 2.609228), it means the null hypothesis is failed to reject.
We do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
This is the concept of algebra, to solve the expression we proceed as follows;
cos 2x-cosx=0
cos 2x=cosx
but:
cos 2x+1=2(cos^2x)
thereore;
from:
cos 2x=cos x
adding 1 on both sides we get:
cos 2x+1=cos x+1
2(cos^2x)=cosx+1
suppose;
cos x=a
thus;
2a^2=a+1
a^2-1/2a-1/2=0
solving the above quadratic we get:
a=-0.5 and a=1
when a=-0.5
cosx=-0.5
x=120=2/3π
when x=1
cos x=1
x=0
the answer is:
x=0 or x=2/3π
Answer:
15 ft
Step-by-step explanation:
Hi, the illustration for the problem is a right triangle with:
hypotenuse (C)= the length of the ladder = L
horizontal side(A) = distance from bottom of the ladder to the building = L - 6
vertical side(B) = distance from the top of the ladder to the bottom of the building = L - 3
So, we can use Pythagoras formula:
A2 +B2= C2
(L – 6 )² + (L-3)² = L²
L²-12L+36+L²-6L+9 =L²
L2 -18L+45 =0
APPLYING QUADRATIC FORMULA WE OBTAIN:
L =15 OR L=3
If L=3
Vertical side = L-3 = 0 (Length can´t be 0)
So L=15
