In: Statistics and Probability
Describe the distribution of sample means (i.e., shape, measure of central tendency and variability) for a sample of n=49 selected from a population with mean of 14 and standard deviation of 7.
Here, population mean()
= 14 , population standard deviation(
)
= 7 and n = 49.
We know that when sample size is large enough (n>30) , the sample means follow a normal distribution in accordancewith the Central limit theorem. Therefore, the shape of the distribution of the sample means will be bell shaped , like a normal curve.
We know that, the mean of the distribution of sample means is
equal to the population mean. Therefore, mean of the distribution =
= 14
We know that, the standard deviation of the distribution of
sample means is equal to the population standard deviation divided
by the square root of n. Therefore, standard deviation =
/
n = 7 / 7 = 1
The sample means are distributed normlly with mean 14 and standard deviation 1.