STA 261 Exam 1 Questions with 100% Correct Answers

Descriptive statistics Correct Answer summarizing the data Ex. Mean, median, standard deviation, graphical displays Inferential statistics Correct Answer drawing conclusions about a population based on a sample Ex. Confidence intervals, hypothesis tests Descriptive statistics vs. Inferential statistics Correct Answer descriptive statistics can summarize the large amount of raw data, but since everything is known for the population, there is nothing to infer Population Correct Answer entire group of individuals or items of interest Sample Correct Answer a subset, part of the entire group or items of interest Parameter Correct Answer a value that is computed from the whole population (fixed value) Statistic Correct Answer a value that is computed from the sample (changes from sample to sample) Categorical variable (qualitative) Correct Answer can not take the mean of, descriptive Ex. Favorite color, zip code, type of pet Use pie chart, bar graph, pareto chart Quantitative variable Correct Answer numerical, measure "how much" of something Use stem plot, stem and leaf plot, histogram, dotplot Discrete data Correct Answer isolated points on a line Continuous data Correct Answer any number in a continuous interval, associated with measuring, usually counts of something, infinite values Ex. Height, weight Frequency vs. Relative frequency Correct Answer frequency: shows decimals, whole numbers Relative frequency: percentages, fractions Measures of center Correct Answer mean, median, mode Measures of variation Correct Answer range, standard deviation