Question

in testing a new drug, researchers found that 10% of all patients using it will have a mild side effect. A random sample of 12 patients using the drug is selected. Find the probability that
A. exactly three will have this mild side effect
B. at least three will have this mild side effect

Answer 1

is 12 enough of a count?

Answer 2

(12 C 3) .10^3 .90^9 maybe?

Answer 3

at least 3 is 1-"2"

Answer 4

if i hit the right buttons, id say A is .0852

Answer 5

B might be .7699 if im remembering it right

Answer 6

there he is :)

Answer 7

binomial this one

Answer 8

yay!! i was right, basically

Answer 9

exactly three is 0.85 and at least 3 would be 0.025? Am i right?

Answer 10

\[P(X=3)=\dbinom{12}{3}(.1)^3(.9)^9\]

Answer 11

1 - exactly2

Answer 12

.... or am i not hitting the right synapses

Answer 13

1-P(1)-P(2) is what i got in me head

Answer 14

at least three
compute
none
\[(.9)^{12}\]
1
\[12\times .1\times (.9)^{11}\] and 2
\[66(.1)^2(.9)^{10}\]
add them up and subtract the result from 1

Answer 15

@ amistre you forgot
\[P(X=0)\] you need that one too

Answer 16

yep

Answer 17

\[P(X\geq 3)=1-(P(X=0)+P(X=1)+P(X=2))\]

Answer 18

let me get a number for the first one

Answer 19

.085
not .85

Answer 20

yes i see that now