Answer:
A darts player practices throwing a dart at the bull’s eye on a dart board. Her probability of hitting the bull’s eye for each throw is 0.2.
(a) Find the probability that she is successful for the first time on the third throw:
The number F of unsuccessful throws till the first bull’s eye follows a geometric
distribution with probability of success q = 0.2 and probability of failure p = 0.8.
If the first bull’s eye is on the third throw, there must be two failures:
P(F = 2) = p
2
q = (0.8)2
(0.2) = 0.128.
(b) Find the probability that she will have at least three failures before her first
success.
We want the probability of F ≥ 3. This can be found in two ways:
P(F ≥ 3) = P(F = 3) + P(F = 4) + P(F = 5) + P(F = 6) + . . .
= p
3
q + p
4
q + p
5
q + p
6
q + . . . (geometric series with ratio p)
=
p
3
q
1 − p
=
(0.8)3
(0.2)
1 − 0.8
= (0.8)3 = 0.512.
Alternatively,
P(F ≥ 3) = 1 − (P(F = 0) + P(F = 1) + P(F = 2))
= 1 − (q + pq + p
2
q)
= 1 − (0.2)(1 + 0.8 + (0.8)2
)
= 1 − 0.488 = 0.512.
(c) How many throws on average will fail before she hits bull’s eye?
Since p = 0.8 and q = 0.2, the expected number of failures before the first success
is
E[F] = p
q
=
0.8
0.2
= 4.
Answer:
10
Step-by-step explanation:
x- intercept is where the equation intersect the x-axis. So, at x-axis y = 0
2x + 4*0 = 20
2x = 20
Divide both sides by 2
2x /2 = 20/2
x = 10
Answer:
Choice C. 14 inches
Step-by-step explanation:
Middle between 12 and 16 inches.
Answer: I'm pretty sure I can help, just give me like 3 minutes..
-Angie
Answer:
The answer is 
.
Step-by-step explanation:
Given:
77.5%.
Now, to write as a fraction or mixed number in simplest form.
77.5%
So, we divide by 10 by removing decimal as decimal is at tenth place.
= 
So, simplifying it:
Now, we change into mixed fraction:
Therefore, the answer is .
