BQA 3123 Test 1 MS State Dr. Ballard
Questions and Answers 100% Verified
Properties of Z-scores Mean of Z-scores, standard deviation of Z-scores is always 1
Density function under curve 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
The estimation process It is the process to estimate a target parameter of the population.
Define a target parameter The target parameter is the unknown population parameter
that we are interested in estimating.
Point Estimator 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.
, Interval Estimator (Confidence Interval) Is a formula that tells us how to use the sample
data to calculate an interval that estimates the target parameter. The CI will have a confidence
level, usually stated as a percentage, aka reliability coefficient.
Conditions for a Large Sample Interval Get a random sample from the target population,
the sample size is sufficiently large, greater than 30. Due to CLT, this condition guarantees that
the sampling distribution of the mean is normal.
Central Limit Theorem Guarantees the sampling distribution of mean is approximately
normal when sample size is sufficiently large
William Gosset Used pen name Students t-distribution and created the t-table. He didn't
work with a student and wasn't a student.
Similarities of Z and T Mound-shaped, symmetry, mean=0
Differences of Z and T T statistic distribution varies more and variability is due to sample
size.
Questions and Answers 100% Verified
Properties of Z-scores Mean of Z-scores, standard deviation of Z-scores is always 1
Density function under curve 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
The estimation process It is the process to estimate a target parameter of the population.
Define a target parameter The target parameter is the unknown population parameter
that we are interested in estimating.
Point Estimator 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.
, Interval Estimator (Confidence Interval) Is a formula that tells us how to use the sample
data to calculate an interval that estimates the target parameter. The CI will have a confidence
level, usually stated as a percentage, aka reliability coefficient.
Conditions for a Large Sample Interval Get a random sample from the target population,
the sample size is sufficiently large, greater than 30. Due to CLT, this condition guarantees that
the sampling distribution of the mean is normal.
Central Limit Theorem Guarantees the sampling distribution of mean is approximately
normal when sample size is sufficiently large
William Gosset Used pen name Students t-distribution and created the t-table. He didn't
work with a student and wasn't a student.
Similarities of Z and T Mound-shaped, symmetry, mean=0
Differences of Z and T T statistic distribution varies more and variability is due to sample
size.
