Slopes
How can we justify a claim about a linear regression model using a confidence interval?
By determining if 0 is contained in the interval
By computing the R-squared value
By finding the p-value
By comparing the slope to the mean value
What does the confidence level reflect in a confidence interval?
The standard error of the slope
The width of the confidence interval
The number of confidence intervals constructed
The percentage of confidence intervals that would contain the true value
Which term refers to the likelihood that a point estimate will fall within a given confidence interval?
Confidence level
Margin of error
Probability value
Sampling variability
How do you interpret the meaning result where upper boundary 95% confidence interval for slope is 5 whilst lower boundary is -1 concerning estimated relationship between explanatory and response variable?
The most likely outcome is that there is no statistically significant linear trend since the interval includes 0.
There could be either positive or negative linear trend but no more than 5 nor less than -1 unit change in response variable per unit change in X-variable.
This indicates a strong positive trend with predicted increase of exactly five units in Y-response to every additional X-unit.
The slope is too small to note any practical significance hence no need to consider it in statistical modeling.
Which type of sampling gives each member of the population an equal chance to be selected?
Judgemental sampling
Simple random sampling (SRS)
Quota sampling
Snowball sampling
What variable represents the point estimate of the of a regression model?
b^3
b^2
(b-1)
b
If a 95% confidence interval for the slope of a regression line includes zero, what is the implication regarding the relationship between the explanatory and response variables?
There is not enough evidence to conclude that there is a significant relationship.
The variability in the data does not affect the slope estimate.
There is conclusive evidence of a strong positive relationship.
Zero falls outside the range of plausible values for the population slope.

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What method involves choosing individuals who are easiest to reach or readily available?
Purposive sampling
Non-probability sampling
Voluntary response sampling
Convenience sampling
What do you call the range of values used to estimate a population parameter at a certain confidence level?
P-value
Standard deviation
Confidence interval
Z-score
When analyzing the slope of a regression model using confidence intervals, why is it important to include zero as an option for comparison?
Because it assists in confirming normal distribution of residuals, thus ensuring model validity for applications in real-world scenarios.
Because it is required by the statistical community to prevent unethical manipulation of results presented publicly.
Because not including zero violates statistical assumptions required for proper regression analysis.
Because including zero allows us to determine whether there exists significance between predictor and response beyond just due chance.