Answer:
a.) The mean of the six layered plywood is 30 mm
The standard deviation is 0.49 mm
b.) That the thickness is less than 28 mm has a probability of 0.000022.
Step-by-step explanation:
There are six layers in a plywood that is considered. It is also given that the layers are independent and normally distributed.
The thickness of the layers of the plywood have a mean, 
= 5 mm
and a standard deviation, 
= 0.2 mm.
a.) Therefore the mean of the six layered plywood is = 6
= 6 × 5 mmm
= 30 mm
The standard deviation of the six layered plywood = 
= 
= 0.49 mm
b.) We are given to find that the probability of the plywood is less than 28 mm thick.
P( thickness < 28 mm)
P( Z < 
) = P(Z < 
) ⇒ P( Z < -4.082) = 0.000022
Answer: 0.65
Step-by-step explanation:
Let A denote that moviegoers were female and B denotes that moviegoers were under age 25.
As per given we have,
P(A)=0.56 P(B)=0.26 P(A∩B)=0.17
Using formula ,
Hence, the probability that a moviegoer is either female or under age 25 = 0.65
Let us say that the procedure of completely filling up the
pool with water is called “1 job”. Therefore the rates of the equipment in
doing the job would be:
<span>Rate of handheld hose = 1 job / 8 minutes ---> 1</span>
<span>Rate of lawn sprinkler = r --->
2</span>
<span>Rate of the two combines = 1 job/ 5 minutes ---> 3</span>
So we are to find the equation to use, in this case, we
simply have to add equations 1 and 2 to get 3:
1 / 8 + r = 1 / 5
Multiplying both sides by 5:
<span>(5 / 8) + 5 r = 1 --->
ANSWER</span>
