Z tests

What is a single sample z-test?

• A test to compare two sample means.
• A method to calculate the median of a sample.
• A statistical test to compare the sample mean to a known population mean.
• A technique for estimating population variance.

What does x bar represent in a z-test statistic?

• x bar represents the standard deviation in a z-test statistic.
• x bar represents the population mean in a z-test statistic.
• x bar represents the variance in a z-test statistic.
• x bar represents the sample mean in a z-test statistic.

What does the standard error of the mean mean?

• The standard error of the mean is a measure of the total population size.
• The standard error of the mean indicates the average of all sample values.
• The standard error of the mean measures the variability of the sample mean as an estimate of the population mean.

What is a P value?

• A P value is the probability of observing results as extreme as the ones obtained, given that the null hypothesis is true.
• A P value measures the effect size of a treatment.
• A P value is the same as the confidence interval.
• A P value indicates the strength of the null hypothesis.

What is NOT an assumption of a one sample z test?

• The data is not a normal distribution

• The sample is randomly selected from the population

• The data is continuous

What is the difference between the variable "N" and "n" in a one sample z-test equation?

• Both 'N' and 'n' represent the same value.
• 'n' represents the sample size, 'N' represents the population size

• 'N' and 'n' are interchangeable terms.
• 'N' is always a variable, while 'n' is a constant.

The one sample z-test is an inferential statistic

• True
• False

We reject the null hypothesis If the p value is less than...

What is the first step of a one-sample z test?

• Select the significance level.
• Determine the sample size.
• Calculate the sample mean.
• State the null and alternative hypotheses.

z score vs. z test

• A z-score is used for regression; a z-test is for correlation.
• A z-score is a value; a z-test is a hypothesis testing method.
• A z-score measures variance; a z-test measures mean differences.
• A z-score is a statistical test; a z-test is a value.