Sampling & Measuring
In statistics, this is the process of selecting a subset of individuals from a population to estimate characteristics of the whole population.
What is sampling?
Every individual has an equal chance; supports unbiased, ethical conclusions.
What is Simple Random Sampling?
This measure of position indicates the percentage of values below a given value in a data set.
What is a percentile?
This shape describes a perfectly normal distribution.
What is a bell curve?
The __________ measures the dispersion of a probability distribution.
What is variance?
A researcher knowingly or unknowingly selects individuals that support a desired outcome. This introduces what type of bias?
What is selection bias?
When a population is divided into subgroups and a random sample is taken from each subgroup, this method is being used.
What is stratified sampling?
A correlation coefficient of 0 means there is this kind of relationship between the variables.
What is no linear relationship?
A contingency table is used to show the relationship between these.
What are two categorical variables?
The relationship among the mean, median, and mode in a symmetric distribution.
What is in a symmetric distribution, the mean, median, and mode are in the center and are equal?
The reason it is inappropriate to calculate the mean of gender data but appropriate for monthly sales data.
What is gender is nominal data representing categories without intrinsic numeric value or order, so averaging "male" and "female" makes no sense?
This sampling method involves dividing the population into naturally occurring groups and then randomly selecting entire groups.
What is cluster sampling?
A correlation coefficient of -0.95 suggests this type of relationship.
What is a strong negative correlation?
This measure tells how spread out the numbers are around the mean.
What is standard deviation?
Includes range, interquartile range, variance, and standard deviation.
What is Measures of Dispersion?
In a normal distribution, approximately what percent of data lies within two standard deviations of the mean?
What is 95%?
In this sampling method, every kth member of the population is chosen after a random starting point.
What is systematic sampling?
To construct a confidence interval for a population mean when the population standard deviation is unknown, you should use this distribution.
What is the t-distribution?
This part of a box plot represents the middle 50% of the data.
What is the interquartile range (IQR)?
This type of skewness occurs when a distribution has a longer tail on the right side.
What is positive skew?
This term describes the difference between a sample statistic and the actual population parameter.
What is sampling error?
Ensures representation from different subgroups in proportion to their sizes in the population.
What is stratified random sampling?
The Z-score is calculated by subtracting the mean and dividing by this value.
What is the standard deviation?
This statistical measure indicates the strength and direction of a linear relationship between two variables.
What is the correlation coefficient?
A strong correlation between two variables means one causes the other.
What is False?