Answer:
a)= 2
b) 6.324
c) P= 0.1217
Step-by-step explanation:
a) The mean of the sampling distribution of X`1- X`2 denoted by ux`-x` = u1-u2 is equal to the difference between population means i.e = 2 ( given in the question)
b) The standard deviation of the sampling distribution of X`1- X`2 ( standard error of X`1- X`2) denoted by σ_X`1- X`2 is given by
σ_X`1- X`2 = √σ²/n1 +σ²/n2
Var ( X`1- X`2) = Var X`1 + Var X`2 = σ²/n1 +σ²/n2
so
σ_X`1- X`2 =√20 +20 = 6.324
if the populations are normal the sampling distribution X`1- X`2 , regardless of sample sizes , will be normal with mean u1-u2 and variance σ²/n1 +σ²/n2.
Where as Z is normally distributed with mean zero and unit variance.
If we take X`1- X`2= 0 and u1-u2= 2 and standard deviation of the sampling distribution = 6.324 then
Z= 0-2/ 6.342= -0.31625
P(-0.31625<z<0)= 0.1217
The probability would be 0.1217
Answer:
k=2 k=-8
Step-by-step explanation:
Answer:
900
Step-by-step explanation:
.6 * 1500
Answer:
Jake is 9, and Jake's dad is 43.
Step-by-step explanation:
Ok, let's start off by putting a variable for Jack's age, A.
We know that Jack's father is 2 less than 5 times, so we can write his as 5x -2.
Now let's make an equation:
52 = x + 5x - 2
We need to isolate the x-values so we need to add 2 on both sides:
54= x + 5x
No we need to add the like terms:
54 = 6x
Finally, we just divide by 6 on each side.
Now we know X = 9 but we're not done yet :)
So because Jake's dad is almost 5 times as much, we first multiply Jack's age by 5. We get 45 but we need to subtract 2 which leaves us with 43.
