Answer:
Correct option: (a) 0.1452
Step-by-step explanation:
The new test designed for detecting TB is being analysed.
Denote the events as follows:
<em>D</em> = a person has the disease
<em>X</em> = the test is positive.
The information provided is:

Compute the probability that a person does not have the disease as follows:

The probability of a person not having the disease is 0.12.
Compute the probability that a randomly selected person is tested negative but does have the disease as follows:
![P(X^{c}\cap D)=P(X^{c}|D)P(D)\\=[1-P(X|D)]\times P(D)\\=[1-0.97]\times 0.88\\=0.03\times 0.88\\=0.0264](https://tex.z-dn.net/?f=P%28X%5E%7Bc%7D%5Ccap%20D%29%3DP%28X%5E%7Bc%7D%7CD%29P%28D%29%5C%5C%3D%5B1-P%28X%7CD%29%5D%5Ctimes%20P%28D%29%5C%5C%3D%5B1-0.97%5D%5Ctimes%200.88%5C%5C%3D0.03%5Ctimes%200.88%5C%5C%3D0.0264)
Compute the probability that a randomly selected person is tested negative but does not have the disease as follows:
![P(X^{c}\cap D^{c})=P(X^{c}|D^{c})P(D^{c})\\=[1-P(X|D)]\times{1- P(D)]\\=0.99\times 0.12\\=0.1188](https://tex.z-dn.net/?f=P%28X%5E%7Bc%7D%5Ccap%20D%5E%7Bc%7D%29%3DP%28X%5E%7Bc%7D%7CD%5E%7Bc%7D%29P%28D%5E%7Bc%7D%29%5C%5C%3D%5B1-P%28X%7CD%29%5D%5Ctimes%7B1-%20P%28D%29%5D%5C%5C%3D0.99%5Ctimes%200.12%5C%5C%3D0.1188)
Compute the probability that a randomly selected person is tested negative as follows:


Thus, the probability of the test indicating that the person does not have the disease is 0.1452.
If we represent Tobin's speed as x, we can write her opponent's speed as
x-2 (since Tobin is 2 more than them). In addition, since it's in miles per hour, and 45 minutes is 3/4 of an hour, we can say that 3/4ths of her speed in miles per hour is how long the race is, so (3/4)(x-2)=distance of race. In addition, since it only took Tobin 30 minutes, and 30 minutes is half an hour, x/2 (half of her miles per hour) is the length of the race, so (3/4)(x-2)=(1/2)x. Expanding it, we get 3x/4-6/4=x/2. Subtracting x/2 (or 2x/4) from both sides, we get x/4-6/4=0 and by adding 6/4 to both sides we get x/4=6/4. Multiplying 4 to both sides, we get that x=6=Tobin's speed in miles per hour
Answer:
13.75
Step-by-step explanation:
66-20- 32 1/4
66-20- 32.25
46-32.25
13.75
Answer:
480,700 sets (first choice)
Step-by-step explanation:
If all 25 questions are different,
When order of selection counts:
P(25,7)
= 25!/(25-7)!
= 15511210043330985984000000/6402373705728000
= 2422728000
When order of selection does not count count:
C(25,7)
=25!/(7!*(25-7)!)
=15511210043330985984000000/(6402373705728000*5040)
= 480,700
Hope this helps, have a nice day.