Answer:
1.12/30 which is equals to 2/5
2.9 more students
3.171*1.50 =$25.65
Step-by-step explanation:
Answer: -4/7
Step-by-step explanation:
To find the slope, let's change the equation to slope-intercept form.
[subtract both sides by 4x]
[divide both sides by 7]

Now, we know the slope is -4/7.
Answer:
a) 2/3
b) 1/3
Step-by-step explanation:
Let X be the random event that measures the time you will have to wait.
Since time is uniformly distributed between 10 and 10:30 in intervals of 1 minute
P(n < X ≤ n+1) = 1/30 for every minute n=0,1,...29.
a)
P( X > 10) = 1 - P(X ≤ 10) = 1 - 10/30 = 2/3
b)
P(10 < X ≤ 20) = (20-10)/30 = 1/3
Answer:
6 months
Step-by-step explanation:
Answer:

Step-by-step explanation:
This is a conditional probability exercise.
Let's name the events :
I : ''A person is infected''
NI : ''A person is not infected''
PT : ''The test is positive''
NT : ''The test is negative''
The conditional probability equation is :
Given two events A and B :
P(A/B) = P(A ∩ B) / P(B)

P(A/B) is the probability of the event A given that the event B happened
P(A ∩ B) is the probability of the event (A ∩ B)
(A ∩ B) is the event where A and B happened at the same time
In the exercise :



We are looking for P(I/PT) :
P(I/PT)=P(I∩ PT)/ P(PT)

P(PT/I)=P(PT∩ I)/P(I)
0.904=P(PT∩ I)/0.025
P(PT∩ I)=0.904 x 0.025
P(PT∩ I) = 0.0226
P(PT/NI)=0.041
P(PT/NI)=P(PT∩ NI)/P(NI)
0.041=P(PT∩ NI)/0.975
P(PT∩ NI) = 0.041 x 0.975
P(PT∩ NI) = 0.039975
P(PT) = P(PT∩ I)+P(PT∩ NI)
P(PT)= 0.0226 + 0.039975
P(PT) = 0.062575
P(I/PT) = P(PT∩I)/P(PT)
