Statistical Studies

A ___ is a large group that includes everything being studied.

• Sample
• Stratified Sampling Method
• Population
• Voluntary-Response

A ___ is a small portion of the population used to gather data from.

• Systematic Sampling Method
• Sample
• Population
• Bias

Why do we randomly select our samples?

• to control every aspect
• reduce bias
• so we don't get the same answers from everyone
• because it is easier to do

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She randomly selects 5 students.

• Convenience Sampling
• Systematic Sample
• Stratified Sample
• Random Sample

How do we calculate the standard deviation of a dataset?

• Square root the dataset's variance

• Square root the dataset's deviance from the mean

• Square the dataset's variance

• Square the dataet's deviance from the mean

What proportion of the population's data do we expect to lie within 2 standard deviations of the mean?

• 68%

• 90%

• 95%

• 99.7%

Find the range of the data 45, 76, 98, 21, 52, 39

• 108

• 2

• 36.5

• 77

What is the median of the data?

• The average value

• The most common value

• The middle value

• The difference between the highest and lowest value

What is the range of the data?

• Find the most common value

• Find the middle value

• Add up all the values in the data then divide by number of values in data

• The difference between the highest and lowest values of the data

When finding the median, you end up with a middle that has two numbers. What do you do?

• Take the higher number

• Take the lower number

• Take both numbers

• Take the average of the two numbers