- | Page
BQA 3123 IVA BALLARD EXAM 1
QUESTION AND ANSWERS 100% CORRECT
Question : Tendency of data to revolve around the middle. It
will cluster around certain values.
Correct answer: Central Tendency
Question : Average
Correct answer: Mean
Question : Most. Might not have one. It is a supplemental value.
Correct answer: Mode
Question : Middle after put in order
Correct answer: Median
Question : Negative Skewed Distribution
Correct answer: If mean is less than median
Question : Positive Skewed Distribution
Correct answer: If mean is greater than median
- | Page
Question : Symmetrical distribution
Correct answer: If mean is equal to median
Question : What influences the mean?
Correct answer: Outliers or extreme values
Question : A measure of variability/spread/dispersion
Correct answer: Range
Question : Limitation of the range
Correct answer: It only uses two values. Specifically, max and
min
Question : Emperical Rule
Correct answer: Is used when we have mound-shaped and
symmetric distribution and it allows us to say about 68% of data will fall within one st. dev from the mean, 95% within two st.dev, and 99.7% within three st. dev.
Question : Normal Distribution
- | Page
Correct answer: Mound-shaped, symmetric, bell curve area
under the curve of 1. Can use area in terms of probability.
Question : Chebyshev's Rule
Correct answer: Is used when we do not know anything about
the distribution of the data and claims at least 3 (75%) of the data will fall within 2 st. dev from the mean.
Question : Tells us how many st. dev above or below the mean
Correct answer: Z-score
Question : Two reasons for using Z-scores
Correct answer: The shape of the z-scores distribution will be
the same as the original distribution of the raw/original score.They will tell us the exact location of the original score within the distribution.
Question : Properties of Z-scores
Correct answer: Mean of Z-scores, standard deviation of Z-
scores is always 1
- | Page
Question : Density function under curve
Correct answer: If a random variable is normal and it is
standardized, its distribution will still be normal. The curve that will represent its distribution will be called the standard normal curve, also z-table
Question : It is the process to estimate a target parameter of the
population.
Correct answer: The estimation process
Question : Define a target parameter
Correct answer: The target parameter is the unknown population
parameter that we are interested in estimating.
Question : Point Estimator
Correct answer: A point estimator of a population parameter is a
rule or formula that tells us how to use the sample data to calculate a single value/number that can be used as an estimate for the target parameter.