Let n = required random sample size.
Assume that the population standard deviation is known as σ.
Let m = sample mean.
At the 95% confidence level, the expected range is
(m - k(σ/√n), m + k(σ/√n))
where k = 1.96.
Therefore the error margin is 1.96(σ/√n).
Because the error margin is specified as 3% or 0.03, therefore
(1.96σ)/√n = 0.03
√n = (1.96σ)/0.03
n = 128.05σ²
This means that the sample size is about 128 times the population variance.
Answer:
Smallest sample size = 128.05σ², where σ = population standard deviation.
Answer:
f(x) = 8(1/2)^x.
Step-by-step explanation:
According to the graph, there is a point at (0, 8) and (1, 4).
That means that when x = 0, y = 8.
8 = a(b)^0
1a = 8
a = 8
That means that a = 8, and when x = 1, y = 4.
4 = 8(b)^1
4 = 8b
8b = 4
b = 4/8
b = 1/2
So, f(x) = 8(1/2)^x.
Hope this helps!
There is only one positive integer which is exactly twice the sum of its digits. find this 2 digit number
Answer:
I only know how to solve it, it is -3
Step-by-step explanation:
-8x+3> or = 18-3x
3>or= 5x+18
-15> or = 5x
x>or=-3
