Means
Which component needs to be added and subtracted from the sample mean to create a confidence interval?
Sample median.
Margin of error.
Population mean.
Sample proportion.
If an outlier is present in your dataset while calculating a confidence interval for a mean, which method would most likely maintain the validity of your interval estimate?
Substitute outlier values with mean values to minimize their effect on interval computation.
Increase your confidence level to account for extra variability introduced by outliers.
Apply robust statistical techniques like trimming or Winsorizing before computing the interval.
Compute the interval as usual and then adjust its width subjectively based on outlier magnitude.
A researcher wants to construct a 99% confidence interval for a population mean. Which of the following z-scores should be used?
2.33
1.96
2.58
2.81
What is one potential consequence of incorrectly using the normal distribution to construct a confidence interval for a population mean when the sample size is small and the standard deviation is unknown?
Increased probability of non-significant results, decreasing the effect size
A narrowed confidence interval, leading to a higher chance of Type I error
Increased likelihood of correctly rejecting the null hypothesis despite violations of assumptions
The widened confidence interval, increasing the risk of falsely stating precision
Which of the following is NOT required when constructing a confidence interval for a population mean?
Confidence level
Sample mean
Sample size
Population standard deviation
If the standard deviation of a population is unknown, which distribution should be used to construct a confidence interval for the population mean?
Binomial distribution
t-distribution
Chi-squared distribution
Normal distribution
In constructing a confidence interval for a population mean, what does '95% confident' imply?
Exactly 95% of all individuals in our sample will have values within this interval.
We expect that if we took many samples, about 95% of them would produce intervals containing the true population mean.
The true population means are found within this range with absolute certainty.
There is only a 5% chance that our single calculated interval does not contain the true population mean.

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Which factor affects the width of a constructed confidence interval?
Sample proportion.
Population standard deviation.
Sample size.
Level of significance.
If researchers divide subjects into blocks based on certain characteristics before randomly assigning them within those blocks what type if design is it?
Block design
Matched pair design
Completely randomized design
Replicated Block Design
The confidence interval for a population mean provides an estimate of:
The range within which the population mean falls.
The range within which the sample size falls.
The range within which the standard deviation falls.
The range within which the sample mean falls.