LEARNING STATISTICS CNSL 503,
THE T-TEST WITH CORRECT
SOLUTIONS
When population standard deviation is known, the z-score is used, when population
standard deviation is unknown, the __ is used - ANSWER-t-score
True/False
Since t-scores are centered normally around the mean and form a bell-shaped
curve, probabilities can be calculated to draw inferences about populations. -
ANSWER-True
___ determine how well the t-distribution approximates the normal distribution of the
z-scores. To calculate for any sample size, n-1 - ANSWER-Degrees of freedom (df)
A t distribution approximately resembles a normal distribution when n=___ -
ANSWER-n=12
T-testing for a one sample test is used when __ - ANSWER-the population mean is
known
In a one sample test, state the possible Ho and Ha hypotheses - ANSWER-Ho:
µ = known population mean
Ha:
µ > known population mean (right tailed)
µ < known population mean (left tailed)
µ ≠ equal known population mean (two tailed)
How to calculate df for one sample tests - ANSWER-n-1
For t-testing, you compute ___ based on a sample statistic rather than using a
standard deviation based on a population parameter - ANSWER-standard error
The __ is centered around the mean, extending to the left and to the right to include
estimated standard error, sx̄. It provides a range of values that would likely contain
the population mean at a given alpha level. - ANSWER-confidence intervals
To increase the range of a confidence interval, ____ - ANSWER-decrease the
significance level
The two types of sample studies include: - ANSWER-1. Independent
2. Paired