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:
A
Step-by-step explanation:
Take a look at the graph starting from the left. You’ll see that on the horizontal line, the graph starts at -4 then starts to go downward until it gets to -2 and it starts going up after that so your first interval is (-4, -2). The line increases from -2 to 2 and then it starts sliding downward again from 2 to 4 so your second decreasing interval is (2, 4).
Answer:
Step-by-step explanation:
we know that
The area of the circle is equal to
where
D is the diameter of the circle
Solve for D
That means-----> Isolate the variable D
Multiply both sides by 4 to remove the fraction
Divide both sides by π
square root both sides
Rewrite
Simplify
