Step-by-step explanation:
It is given that,
The length of section 1 is 0.75 m and the length of section 2 is 15/100 m. The total length of the section is equal to the sum of section 1 and section 2. So, we will add them as follows :

So, the length of the section is 0.9 m or 9/10 m
Answer:
Dan = 68
bobbi = 62
Step-by-step explanation:
Let Bobbi's height = b
Let Dan's height = d
the following equations can be determined from the question
b + d = 130 eqn 1
3b - d = 118 eqn 2
Multiply eqn 1 by 3
3b + 3d = 390 eqn 3
Substract eqn 2 from 3. this gives
4d = 272
d = 68
Substitute for d in eqn 1
b + 68 = 130
b = 62
Answer:
-37/5= y
x=11/5
Step-by-step explanation:
4x-3y=31
-3y=-4x+31 regroup it to match the other
-2 y=(2x-3)(-2) multiply by -2 to get -4x
-3y=-4x+31
-2y=-4x+6 adding
-5y=37 divide
-37/5= y
4x-3(-37/5)=31
x=11/5
First multiply
.45*647= 291.15
291.15 is the number of people that attended
subtract 291.15 from 647 and you get 355.85 wait.. but that's not possible so just round it so the answer to your question is 355 people did not attened
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)
