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:
22.5km per hour
Step-by-step explanation:
We need to find surface area, so we can imagine breaking it up into face net.
There will be 18 × 18 square base, four 18 × 40 rectangles, and four triangles with base 18 and height 13.
So the surface area would be sum of these areas.
That would be 18×18 + 4( 18 × 40 ) + 4( (1/2) 18×13 ) = <span>3672
Final answer: 3672 m</span>²
Hope this helps.
Step-by-step explanation:
Represent Wilbur with W and Orville with O
The equation connecting both flights is
W - 120 = O
W = 364 feet
364 - 120 = 246
O = 246