Question

a student guesses the answer to 6 question on a true-false quiz find the probability that the indicated number of guesses are correct :exacly 4

Answer 1

Use the binomial probability distribution formula

P(X = x) = (n C x)*(p)^(x)*(1-p)^(n-x)

P(X = 4) = (6 C 4)*(0.5)^(4)*(1-0.5)^(6-4)

P(X = 4) = (6 C 4)*(0.5)^(4)*(0.5)^(6-4)

P(X = 4) = (15)*(0.5)^(4)*(0.5)^2

P(X = 4) = (15)*(0.0625)*(0.25)

P(X = 4) = 0.234375


So the probability of getting exactly 4 questions correct is 0.234375

Answer 2

thank you so much.

Answer 3

you're welcome

Answer 4

give the value of the expression 11C4
a)330
b)220
c)110
d)550

Answer 5

give the value of the expression 11C4
a)330
b)220
c)110
d)550

Answer 6

n C r = (n!)/(r!(n-r)!)


11 C 4 = (11!)/(4!*(11-4)!)


11 C 4 = (11!)/(4!*7!)


11 C 4 = (11*10*9*8*7!)/(4!*7!)


11 C 4 = (11*10*9*8)/(4!)


11 C 4 = (11*10*9*8)/(4*3*2*1)


11 C 4 = (7920)/(24)


11 C 4 = 330

Answer 7

log of base 9 +log base of 2 a=log base 2 11

Answer 8

Can you draw this one out?