The new mean age will be greater than 14.2 years because the teacher is older than the previous mean.
Answer:
30
Step-by-step explanation:
Just insert the value of x into the equation.
x = 3 right?
6^2 + 3 - 3^2 because x = 3
36 + 3 - 9 = 39 -9 = 30
:D
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:
A) The annual multiplier was 1.0339; the annual increase was 0.0339 of the value.
B) 3.39% per year
C) $182,000
Step-by-step explanation:
A) Let's let t represent years since 1987. Then we can fill in the numbers and solve for r.
165000 = 100000(1 +r)^15
1.65^(1/15) = 1 +r . . . . . divide by 100,000; take the 15th root
1.03394855265 -1 = r ≈ 0.0339
The value was multiplied by about 1.0339 each year.
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B) The value increased by about 3.39% per year.
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C) S = $100,000(1.03394855265)^18 ≈ $182,000