Module 5 The t-Test Comprehensive
Questions (Frequently Tested) with
Verified Answers
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
A larger sample size ___ standard error which reduces margin of error - Answer: reduces
A 95% confidence interval tells a researcher __ - 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.
A 95% confidence intervals between -0.002 and 0.9205 is reported in research as: - Answer:
95% CI [-0.002, 0.9205]
Cohen's d calculates effect size to determine - Answer: the absolute magnitude or size of the
treatment.
The two types of sample studies include: - Answer: 1. Independent
2. Paired
The two types of independent studies include: - Answer: 1. independent measure design
2. between subject deisgn
Questions (Frequently Tested) with
Verified Answers
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
A larger sample size ___ standard error which reduces margin of error - Answer: reduces
A 95% confidence interval tells a researcher __ - 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.
A 95% confidence intervals between -0.002 and 0.9205 is reported in research as: - Answer:
95% CI [-0.002, 0.9205]
Cohen's d calculates effect size to determine - Answer: the absolute magnitude or size of the
treatment.
The two types of sample studies include: - Answer: 1. Independent
2. Paired
The two types of independent studies include: - Answer: 1. independent measure design
2. between subject deisgn
