Question

Count the number of fives in 7 dice rolls. If it is binomial, give values for n and p. Enter the exact answer.

n =

p =

Answer 1

Solution:

7 dice are rolled which is similar to rolling a die 7 times,

thus n = number of trials = 7.

X = Number of fives in  7 dice rolls.

p = probability of getting a number "5" in a single roll

p = 1/6

Since we have total 6 sides for a die and each side has an equal chance that is equal probability, thus probability of getting a number "5" is 1 out of 6 , that is:1/6

Since trials that is rolling of dice are independent, probability of getting a number "5" is same all over the 7 trials, distribution of X = Number of fives in  7 dice rolls is Binomial.

Thus values of n and p are:

n = 7

p = 1/6