Answer:
Mean for a binomial distribution = 374
Standard deviation for a binomial distribution = 12.97
Step-by-step explanation:
We are given a binomial distribution with 680 trials and a probability of success of 0.55.
The above situation can be represented through Binomial distribution;
where, n = number of trials (samples) taken = 680 trials
r = number of success
p = probability of success which in our question is 0.55
So, it means X <em>~ </em>
<em><u>Now, we have to find the mean and standard deviation of the given binomial distribution.</u></em>
- Mean of Binomial Distribution is given by;
E(X) = n 
p
So, E(X) = 680 0.55 = 374
- Standard deviation of Binomial Distribution is given by;
S.D.(X) = 
= 
= 
= 12.97
Therefore, Mean and standard deviation for binomial distribution is 374 and 12.97 respectively.
Answer:
z = -12
Step-by-step explanation:
The given system of equations is:
xy/(x + y) = 1 ...........................(1)
xz/(x + z) = 2...........................(2)
yz/(y + z) = 3...........................(3)
From (1): x + y = xy
=> y = xy - x
y = x(y - 1)
x = y/(y - 1).......................................(4)
From (2): 2(x + z) = xz
=> 2x + 2z = xz
2x = xz - 2z
2x = z(x - 2)
z = 2x/(x - 2) ....................................(5)
From (3): 3(y + z) = yz
=> 3y + 3z = yz
3y = yz - 3z
3y = z(y - 3)
z = 3y/(y - 3)....................................(6)
Comparing (5) and (6)
2x/(x - 2) = 3y/(y - 3)
2x(y - 3) = 3y(x - 2)
2xy - 6x = 3xy - 6y
6(y - x) = xy .................................(7)
But from (1): xy = x + y
Using this in (7), we have
6(y - x) = x + y
6y - y - 6x - x = 0
5y - 7x = 0
5y = 7x
x = 5y/7................................................(8)
Using this in (4)
5y/7 = y/(y - 1)
1/(y - 1) = 5/7
(y - 1) = 7/5
y = 1 + 7/5
y = 12/5..........................................(9)
Using this in (8)
x = 5(12/5)/7 = 12/7 .......................(10)
Using (10) in (5)
z = 2x/(x - 2)
z = 2(12/7) ÷ (12/7 - 2)
= 24/7 ÷ -2/7
= 24/7 × (-7/2)
= -24/2 = -12
z = -12.
Answer:
3
Step-by-step explanation:
i dont know how to show the work i did it in my head
It's not possible nothing but 1 times 5 is the only thing that multiplies to 5 and 1+5 doesn't equal 4
Answer:
-1.8 =x
Step-by-step explanation:
12(x+3)=-8x
Distribute
12x +36 = -8x
Subtract 12x from each side
12x-12x +36 = -8x-12x
36 = -20x
Divide each side by -20
36/-20 = -20x/-20
-9/5 = x
Changing to decimal form
-1.8 =x
