Use the information below to answer the questions:

Stadium	Capacity(thousands)
Rungrado May Day (N.Korea)	150
Salt Lake (India)	120
Beaver (Pennsylvania)	107.28
Michigan	106.2
Estadio Azteca (Mexico)	105

Calculate:
a) the mean
b) the variance
c) the standard deviation

Samples

In a new study on College lifestyle, a professor at K decides he will survey K students on how their lifestyles are. To get his sample the professor goes through the school's directory and picks every 25th student to use for the survey. This type of sample is:

A) Stratified random sample

B) Systematic sample

C) Cluster sample

Price of Gold

The following data represents the average prices of gold (in dollars per fine ounce) for the years 1981 to 2000. Find the mean, variance, and standard deviation of the data. What percentage of the data lies within two standard deviations of the mean?

460, 376, 424, 361, 318,
368, 478, 438, 383, 385,
363, 345, 361, 385, 386,
389, 332, 295, 280, 280


(Source: U.S. Bureau of Mines and U.S. Geological
Survey)

Calculating the Standard Error

The sample mean for the cost of an accounting book is $185.00, based on a sample of 100 people. Calculate the standard error for an accounting book.

Practice Problem

A recent survey took a sample size of 10,000 people and asked them too answer questions on how much money they spend on junk food each week? With a standard deviation of $15.75, calculate the standard error.

A.) 1.25

B.) .1525

C.) .1435

D.) .1575

Eat More Granola Bars ....... and practice more......

Calculate the sample standard deviation using the following data about Granola Bars.

Granola Bars	Price (Dollar) per Box
Nature Valley	5.90
Quaker	4.36
Power Bar	10.00
Meijer	4.90
Fiber One	5.90

Practice Problem

A group does a survey by calling 1,000 households in Kalamazoo. Every household number in Kalamazoo was randomized and put onto a list, the surveyors then called every 5th number. This is an example of what kind of sampling technique?

A) Simple Random Sample
B) Systematic Sample
C) Stratified Random Sample
D) Cluster Sample