A certain insecticide kills 60% 60 % of all insects in laboratory experiments. A sample of 7 insects is exposed to the insecticide in a particular experiment. What is the probability that exactly 4 insects will survive? Round your answer to four decimal places.

The probability that exactly 4 insects will survive = 0.2903.

Step-by-step explanation:

Given : The proportion of all insects in laboratory experiments killed by insecticide = 60%=0.60

Since , by using insecticide only two outcomes are possible either it kills or not kills , so we can use binomial.

Sample size of insects = 7

By using binomial probability formula : , where x is binomial variable , n = sample size and p is the probability of getting success.

Let x be the number of insects survived.

As per given , we have

n=7 , p=0.60

Now , the probability that exactly 4 insects will survive :

Hence, the probability that exactly 4 insects will survive = 0.2903

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!