Answer:
Hence the correct option is option c has a Binomial distribution with n=21 and p=50%.
Explanation:
1)
A coin is tossed 19 times,
P(Head)=0.5
P(Tail)=0.5
We have to find the probability of a total number of heads in all the coin tosses equals 9.
This can be solved using the binomial distribution. For binomial distribution,
P(X=x)=C(n,x)px(1-p)n-x
where n is the number of trials, x is the number of successes, p is the probability of success, C(n,x) is a number of ways of choosing x from n.
P(X=9)=C(19,9)(0.5)9(0.5)10
P(X=9)=0.1762
2)
A fair die is rolled twice.
Total number of outcomes=36
Possibilities of getting sum as 9
S9={(3,6),(4,5)(5,4),(6,3)}
The total number of spots showing in all the die rolls equals 9 =4/36=0.1111
3)
The event of getting a good number of spots on a die roll is actually no different from the event of heads on a coin toss since the probability of a good number of spots is 3/6 = 1/2, which is additionally the probability of heads. the entire number of heads altogether the tosses of the coin plus the entire number of times the die lands with a good number of spots has an equivalent distribution because the total number of heads in 19+2= 21 tosses of the coin. The distribution is binomial with n=21 and p=50%.