Week 4 is about Variance and Standard Deviation. Two sets of data can have the same mean, median and mode yet not be similar at all. One might have a range of 30 points while another has a range of 100 points. Standard deviation tells you how widely dispersed the data of a distribution is.

Note: Approximately 70% (actually 68.26% in a large distribution) of data points in a distribution are within 1 standard deviation of the mean. This allows us to apply probability to statistics to make inferences about a population.

Do this:Add your age and the Calendar day you were born.If you are 30and were born on May 15,your sum is 30+15=45.

Now using that number,answer this question:If a normal distribution has a mean ofthat number (the one you found),and a standard deviation of 14, between what two values can we find approximately 70% of the data points in the distribution.