MODULE 5: THE T-TEST (PORTAGE
LEARNING STATISTICS CNSL 503,
THE T-TEST) QUESTIONS AND
ANSWERS 100% CORRECT
Question : When population standard deviation is known, the
z-score is used, when population standard deviation is unknown, the __ is used
Correct answer: t-score
Question : 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.
Correct answer: True
Question : ___ determine how well the t-distribution
approximates the normal distribution of the z-scores. To calculate for any sample size, n-1
Correct answer: Degrees of freedom (df)
Question : A t distribution approximately resembles a normal
distribution when n=___
Correct answer: n=12
Question : T-testing for a one sample test is used when __
Correct answer: the population mean is known
Question : In a one sample test, state the possible Ho and Ha
hypotheses Correct 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)
Question : How to calculate df for one sample tests
Correct answer: n-1
Question : For t-testing, you compute ___ based on a sample
statistic rather than using a standard deviation based on a population parameter
Correct answer: standard error
Question : 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.
Correct answer: confidence intervals
Question : To increase the range of a confidence interval,
____
Correct answer: decrease the significance level
Question : A larger sample size ___ standard error which
reduces margin of error
Correct answer: reduces
Question : A 95% confidence interval tells a researcher __
Correct answer: A 95% confidence interval tells a researcher
that they can be 95% confidence that the true population mean falls between the lower end -> higher end.
Question : A 95% confidence intervals between -0.002 and
0.9205 is reported in research as:
Correct answer: 95% CI [-0.002, 0.9205]
Question : Cohen's d calculates effect size to determine
Correct answer: the absolute magnitude or size of the
treatment.
Question : The two types of sample studies include:
Correct answer: 1. Independent
- Paired
Question : The two types of independent studies include:
Correct answer: 1. independent measure design
- between subject deisgn