Question

Assume a study of sample size n was conducted and the sample mean was found to be  and the sample variance s². Which of the below is the correct way to calculate the standard error of the mean of the sample?

Suppose you found the prices for 11 recently sold puppies in your area and recorded them in the table below. The next few questions will use this sample.

Price ($):
1437.78
1902.35
1657.76
2057.27
1823.35
1816.12
1808.84
1654.00
1815.81
1968.85
1703.11

Calculate the sample mean of the average selling price of puppies sold in your area.

Calculate the sample variance of the average selling price of puppies sold in your area.

Answer 1

Solution: The formula of sample mean() and sample standard variance(s^2) for the raw data is as follows:
Mean =

=
Standard deviation =

Let's make table to find the required sums:

From the above table, we get


and n = 11
Plugging these values in the above formulas of , and σ, we get

and

Calculate the sample mean of the average selling price of puppies sold in your area.
Answer: Sample mean = = 1785.93
Calculate the sample variance of the average selling price of puppies sold in your area.
Answer: Sample variance = 28626.88