Chapters 7 and 8 Test 3 Review Flashcards
If alpha is known, what are the assumptions that come with it?
That it is a simple random mean.
It is a normal population or a large sample size.
What is a sample error?
It is the error that can occur from using a sample to estimate a population’s characteristics.
What does the term “bar x” signify?
Sample mean
What does “sample distribution of a sample mean” mean?
It is the distribution of all possible sample means of sample size (bar x).
What does the xi stand for in the equation for the population standard deviation?
each of the numbers in the sample size
What does the “u” represent in the equation for the population standard deviation?
the mean of the population
What does the “N” stand for in the equation for the population standard deviation?
the size of the population
How do we find the standard deviation of the means of little samples of a population?
by using the formula for standard deviation
What is the central limit theorem?
For a relatively large sample size, the variable bar x is approximately normally distributed, regardless of the distribution of the variable under consideration.Increased sample sized makes this even better.
What is considered a large sample space?
30
How do you find the standard deviation of bar x?
standard deviation (of bar x)= standard deviation/ square root of n
What is the formula for finding the sampling distribution of a sample mean?
For the mean: (ux=u) the mean of the population is equal to the mean of the sample size
For the standard deviation: sigma (x)= sigma/ square root of n
Approximately 68% of all possible samples have means that lie within what of the population u?
sigma over square root of n
Approximately 95% of all possible samples have means that lie within what of the population u?
2 sigmas over the square root of n
Approximately 99/7% of all possible samples have means that lie within what of the population u?
3 sigmas over the square root of n
