Means
What is the effect of performing a one-tailed test instead of a two-tailed test?
Decreased power and increased risk of a type I error
Decreased power and decreased risk of a type I error
Increased power and increased risk of a type I error
Increased power and decreased risk of a type I error
What does the p-value represent in a hypothesis test?
The degrees of freedom for the test
The difference between the sample mean and the hypothesized mean
The standard deviation of the sample
The likelihood of obtaining the observed results by chance alone
When summarizing data, what term describes the average distance between each data point and the mean?
Margin of error
Variance
Range
Standard deviation
Which assumption must not be violated to perform a valid test for a population mean when using a large enough sample size?
The sampled observations must be independent.
There is an unequal variance in two populations being compared.
All observations come from populations with different shapes.
Data points are collected without random sampling or assignment.
Which consideration can affect power of the test when conducting hypothesis testing?
The directionality specified before running calculations
The labeling system used on observed outcomes
The participants' understanding of their role during data collection
The significance level chosen
What is typically required before performing a test on the population mean?
Memorizing statistical formulas
Interviewing every member of the population
Choosing an appropriate color for the graph
Gathering a random sample
What does it indicate if we obtain a p-value lower than our significance level when testing whether there's an increase in average time spent on homework?
We fail to reject the null hypothesis and conclude there’s no increase in average time on homework.
The test was inconclusive; hence we cannot make any inference about students' homework time.
We reject the null hypothesis suggesting evidence for increased average time on homework.
We confirm that our sample data perfectly represents all students’ average time spent on homework.

How are we doing?
Give us your feedback and let us know how we can improve
Which of the following is a method for collecting data to test a hypothesis about a population mean?
Solving a quadratic equation
Calculating an integral
Writing a computer program
Conducting a survey
What is often used as an estimate of population variance when calculating standard errors for hypothesis tests concerning means?
Sample variance ()
Sample interquartile range
Sample range
Population variance
When conducting a hypothesis test for a population mean, how does an increase in sample variability affect the size of your confidence interval?
It has no effect on the size of your confidence interval.
It decreases the size of your confidence interval.
It causes the confidence interval to shift but not change in size.
It increases the size of your confidence interval.