Answer:
30
Step-by-step explanation:
40/100 x 50= 20
50-20=30
Answer:
b. A binomial variable with 25 independent trials
Step-by-step explanation:
The conducted experiment is binomial experiment because outcome can be divided into success or failure. The success would be the people who read novel in the past year and also responses are independent of each other. We have to find the number of trials n in the given problem.
we are given that variance of R=6 and p=probability of success=0.4.
We know that variance of binomial distribution is
Variance=npq
where q=1-p=1-0.4=0.6.
By putting the values in variance formula, we can get the value of n.
6=n*0.4*0.6
6=0.24*n
n=6/0.24
n=25
Hence, random variable R is a binomial variable with 25 independent trials.
Answer: C
Step-by-step explanation:
1+2e^x+1=9
2e^x+1=9-1
e^x+1= 8/2
e^x+1 = 4
Here we can applicate the Ln:
ln e^x+1 = ln 4
Applicating the log property for exponent:
(x+1).ln e = ln 4
Ln e = 1, so:
x+1 = ln 4
x = ln 4-1
The range is 13 because 115-102 is 13
When a quadratic equation ax^2+bx+c has a double root, the discriminant,
D=b^2-4ac=0
Here
a=2,
b=b,
c=18
and
D=b^2-4ac=b^2-4*2*18=0
solve for b
b^2-144=0
=> b= ± sqrt(144)= ± 12
So in order that the given equation has double roots, the possible values of b are ± 12.
