Answer:
0.8213
Step-by-step explanation:
-This is a binomial probability problem given by the function:

Given that n=21 and p=0.2, the probability that she experience a delay on at least 3 days is calculated as:

Hence, the probability that she experience delay on at least 3 days is 0.8213

As we have to solve for b, it means we have to isolate b
So first of all subtract
from both sides
So we get

Now we need b , but its b^2 , so we can take square root on both sides.
taking square roots on both sides

Hence option B is correct
The slope of her function represents the amount she earns per door that she knocks on.
Answer:
option-C
Step-by-step explanation:
we are given
Let P(A)=0.5
P(B)=0.9
P(A and B)=0.15
we know that

now, we can plug values


but we have
P(A)=0.5
we can see that both are not equal

so, A and B are not independent
so, option-C........Answer