Standard Deviation

What is the disadvantage of standard deviation as a statistical tool?

Empirical Formula

What is the empirical formula used for?

Increasing accuracy of standard error

Using the equation for calculating standard error as a reference, how are researchers able to increase accuracy.

Relationship Between Variables

Find the sample covariance of the data below and tell if the variables have a direct or inverse relation.

x	y
2	5
4	11
6	13
8	17
10	21

Find the Coefficient of Variation

Calculate the coefficient of variation first finding the mean and the standard deviation using this data set:

50, 52, 38, 65, 57, 48, 60, 53, 55, 44

survey design question

In the survey questions, why should the questions be in a certain order?

How do prices of sandals vary?

Here is the list of prices ($) for sandals at payless.com:
20, 15, 25, 17, 27, 23, 10, 28

1. What is the average price of a pair of sandal?
2. How do the prices of sandals vary compared to the average price?