9- t-statistic Flashcards
what is the major CON of using a z-score for a hypothesis testing?
requires more information than is usually available
the estimated standard error is used…..
the estimated standard error is used as an estimate of the real standard error when the value is unknown
the t statistic (an alternative to z) is used….
is used to test a hypothesis about an unknown POPULATION MEAN, when the value of a standard deviation is also unknown
the degrees of freedom formula for a t- static is….
df= n-1
t distribution is….
the compete set of t values computed for every possible random sample for a specific sample size (n) or a specific degrees of freedom (df)
the exact shape of a t distribution changes with _______.
the exact shape of a t distribution changes with df.
the null hypothesis for a t statistic states that ______________.
the null hypothesis for a t statistic states that the treatment has no affect (MEAN IS UNCHANGED).
all you need to compute a t-statistic is a _______ and a _________.
all you need to compute a t-statistic is a NULL HYPOTHESIS and a SAMPLE from the unknown POPULATION.
a ______ value for standard error, produces a ______ t value.
a larger value for standard error, produces a smaller t value (CLOSER TO ZERO)
any factor that influences the standard error, also affects the __________.
any factor that influences the standard error, also affects the likelihood of rejecting H0.
the larger the variance, the ______ the error.
the larger the variance, the LARGER the error.
the large variance, the ______ likely to find affect.
the large variance, the LESS likely to find affect.
large variance = scores are __________
large variance = scores are WIDELY SCATTERED
the larger the sample, the ______ error.
the larger the sample, the SMALLER error.
larger sample size, produces ____ t value, and ____ likely to find affect.
larger sample size, produces LARGER t value, and MORE likely to find affect.
