A null hypothesis is a statement where there is no association between the two groups you're talking about.
Complete Question
The complete question is shown on the first uploaded image
Answer:
a) 0.88
b) 0.02
c) 0.01
d) 0.99
Step-by-step explanation:
Step one: State the given parameters



Step 2 : Obtain the probability that a unit does not have a type 1 defect
= 
= 
= 0.88
Step 3 : Obtain the probability that a unit has both type 2 and 3 defect?
The probability of the unit having both type 2 and type 3 defect is denoted as 
This is calculated as

= 0.02
Therefore P(D_{2} n D_{3} ) = 0.02
Step 4 : Obtain the probability that the unit has both a type 2 and type 3 ,but not a type 1 defect
Let
denote the probability that the unit has both a type 2 and type 3 ,but not a type 1 defect.
This can be calculated as follows :

= 0.02 - 0.01
= 0.01
Step 4 : Obtain the probability that a unit has at most two defects
P(at most 2 defects) = 1 - P(all three defects)
= 
= 1 - 0.01
= 0.99
Answer:
452.39
Step-by-step explanation:
The question is asking for the area of the pool, so use the circle area formula, which is A=
. In the formula, A is the area and r is the radius. The question gives us the diameter, so divide that by 2 to get the radius. Therefore the equation is A=
, then solve to get 452.39.