The Basics
Characteristics
Study or Experiment?
Types of sampling
Normal Distribution
100
The science of collecting, organizing, summarizing and analyzing information?
Statistics
100
Variables
What are characteristics of individuals within a population called?
100
Seventh grade students are randomly divided into two groups. One group is taught math using traditional techniques; the other is taught using a reform method. After 1 year, each group is given a test to compare proficiency. What is this called?
Designed experiment
100
separating population into homogeneous groups called strata and obtaining a random sample from each strata
Stratified Sampling
100
The z-score formula
What is
z = (X - mu)/sigma
200
The entire group of individuals to be studied
A Population
200
A type of variable based on attributes
qualitative variable
200
A poll is conducted in which 500 people are asked whom they plan to vote for in the upcoming election. What is this?
Observational Study
200
method of sampling every kth individual
Systematic Sample
200
A normal distribution has a mean of 23 and a standard deviation of 4. What is the value one standard deviation above the mean?
What is 27?
300
A subset of a population
A sample
300
What is a numerical measure called in terms of variables?
Quantitative Variable
300
What is an experiment
300
Generic term for selecting a sample randomly
Simple random sample
300
A forest products company claims that the amount of usable lumber in its harvested trees averages 172 cubic feet and has standard deviation of 12.4 cubic feet. Assume that these amounts have approximately a normal distribution. What percent of trees contains more than 147.2 cubic feet?
What is 97.5%
400
What a single person referred to in statistics
Subject
400
What is a variable that has an infinite number of possible values?
Continuous Variable
400
Two things that are required for an experiment
What are random sample and random assignment?
400
A way of sampling by taking chunks of a population
Cluster Sample
400
On average, students do 45 minutes of homework with a stand. dev. of 5. What percent of students do 35-45 mins of homework?
What is 47.5%?
500
Overall, what statistics give us that we look at
Data
500
What is a variable in which it can be counted and is finite?
Discrete Variable
500
Do abandoned children placed in foster homes do better than similar children placed in an institution? The Bucharest Early Intervention Project found that the answer is a clear “Yes.” The subjects were 136 young children abandoned at birth and living in orphanages in Bucharest, Romania. Half of the children, chosen at random, were placed in foster homes. The other half remained in the orphanages. (Foster care was not easily available in Romania at the time and so was paid for by the study.)
What conclusions can we draw from this study?
We can not make inference about the population (no random sampling). We can make inference about cause and effect (random sampling). We can conclude that foster homes caused children to do better.
500
A magazine called "Robots weekly" sends out a survey to its subscribers to see if they would support a law that requires the government to support more money for robot development. What kind of issue is this?
Sampling Bias
500
GPAs of freshman biology majors at a certain university have approximately the normal distribution with the mean 2.87 and the standard deviation is 0.34. What percent of freshman biology majors have GPA above 3.55?
What is 2.5%