ST 260 Exam 3 Questions and Answers 2024
Define Central Limit Theorem ** Answ** the sampling distribution of the mean is
approximately normal no matter what the underlying distribution is as long as the sample size is
large enough (n>=30)
(T/F) If the underlying distribution of the variable of interest is normal, then we can assume that
the distribution of sample means is also normal, regardless of the sample size. ** Answ**
true
if you know the population standard deviation, you use which statistic? ** Answ** use z
table (standard deviation/ sq. root of sample size n)
if you do NOT know the population standard deviation, you use which statistic? ** Answ**
use t table (sample standard deviation/ sq. root of sample size n)
(T/F) as the level of confidence gets larger (95%, 99% etc) the width of the interval gets smaller
** Answ** false
level of confidence and width of interval are __________________ related ** Answ**
directly
**if you are more confident in a situation, the interval of the graph will be larger
sample size and confidence interval width are______________ related ** Answ** inversely
**a larger sample size has more people so you are less confident about the data
(T/F) the t distribution is essentially the same as the standard normal distribution at large (n>100)
sample sizes ** Answ** true
Define Central Limit Theorem ** Answ** the sampling distribution of the mean is
approximately normal no matter what the underlying distribution is as long as the sample size is
large enough (n>=30)
(T/F) If the underlying distribution of the variable of interest is normal, then we can assume that
the distribution of sample means is also normal, regardless of the sample size. ** Answ**
true
if you know the population standard deviation, you use which statistic? ** Answ** use z
table (standard deviation/ sq. root of sample size n)
if you do NOT know the population standard deviation, you use which statistic? ** Answ**
use t table (sample standard deviation/ sq. root of sample size n)
(T/F) as the level of confidence gets larger (95%, 99% etc) the width of the interval gets smaller
** Answ** false
level of confidence and width of interval are __________________ related ** Answ**
directly
**if you are more confident in a situation, the interval of the graph will be larger
sample size and confidence interval width are______________ related ** Answ** inversely
**a larger sample size has more people so you are less confident about the data
(T/F) the t distribution is essentially the same as the standard normal distribution at large (n>100)
sample sizes ** Answ** true
