Errorless Answers.
A company developed a smartphone whose average lifetime is unknown. In order to estimate the
average, 200 smartphones are randomly selected from a large production line and tested; their
average is found to be 5 years. The 200 smartphones represent: correct answers a sample
Significance level correct answers Measures the reliability of a statistical inference
inferential statistics correct answers Process of using sample statistics (mathematics) to draw
conclusions about population parameters
mutually exclusive correct answers Events that cannot occur at the same time.
sampling error correct answers the difference between the results of random samples taken at the
same time
non-sampling error correct answers occurs when the sample data are incorrectly collected,
recorded, or analyzed. Three types of errors: data acquisition errors, non-response errors (or
bias), selection bias
Design of a good survey components correct answers short survey, short/simple questions, start
with demographic questions, ues dichtomous (yes-no) and multiple choice
Direct observation correct answers example: counts backpacks on campus for a day
stratified random sample correct answers a sample from selected subgroups of the target
population in which everyone in those subgroups has an equal chance of being included in the
research
, example: The manager of a customer service division wants to know if the customers in the past
12 months are satisfied with their purchase of CD's. There are four types of CD's.
Joint Probability correct answers the probability of the intersection of two events
Union of two events correct answers The union of events A and B is the event containing all
sample points that are in A or B or both
Marginal Probability correct answers the probability of a single event without consideration of
any other event
Conditional Probability correct answers the likelihood that a target behavior will occur in a given
circumstance
Bayes Law correct answers calculates posterior probability
exhaustive correct answers including everything possible; very thorough or complete
Central Limit Theorem (CLT) correct answers The name of the theorem stating that the sampling
distribution of a statistic (e.g. x ) is approximately normal whenever the sample is large and
random. Allows us to draw conclusions about the population based on strictly sample data.
sampling distribution of the mean correct answers 1. the sampling distribution of the mean has a
different mean from the original population
2. the standard deviation of the sampling distribution of the mean is referred to as the standard
deviation
3. if the original population is not normally distributed, the sampling of the mean will be normal