Answer:
what??????????
Step-by-step explanation:
Remember P.E.M.D.A.S
57 - 12 ÷ 4 · 3
= 57 - 3 · 3
= 57 - 9
= 48
I wanna say 60 but i dont know
The answer is c because it makes the most sense
Answer:
Se=1.2
Step-by-step explanation:
The standard error is the standard deviation of a sample population. "It measures the accuracy with which a sample represents a population".
The central limit theorem (CLT) states "that the distribution of sample means approximates a normal distribution, as the sample size becomes larger, assuming that all samples are identical in size, and regardless of the population distribution shape"
The sample mean is defined as:

And the distribution for the sample mean is given by:

Let X denotes the random variable that measures the particular characteristic of interest. Let, X1, X2, …, Xn be the values of the random variable for the n units of the sample.
As the sample size is large,(>30) it can be assumed that the distribution is normal. The standard error of the sample mean X bar is given by:

If we replace the values given we have:

So then the distribution for the sample mean
is:
