Stats Test 2 Review
(True/False) In a histogram, all class intervals must be of equal width.
True
(True/False) Methods for summarizing data make up the branch of statistics called descriptive statistics.
True
Skewed Right (positively skewed)
Data is pushed left, lack of data on right
Bar Chart
A chart with bars whose lengths are proportional to quantities
Histogram
A graph of vertical bars representing the frequency distribution of a set of data.
Stem and Leaf plot
A method of graphing a collection of numbers by placing the "stem" digits (or initial digits) in one column and the "leaf" digits (or remaining digits) out to the right.
Describing Numerical Data
C- Center (mean or median) U- Unusual characters/numbers S- Spread (variance or range) S- Shape (skew and modal)
(Categorical or Numerical) Gender
Categorical
(Categorical or Numerical) Maturation (young/adult)
Categorical
(Discrete or Continuous) the daily high temperature
Continuous
(Discrete or Continuous) the fraction of material in a statistics class understood by a student
Continuous
(Discrete or Continuous) the height of a book
Continuous
(Discrete or Continuous) the weight of babies born at a large hospital
Continuous
Skewed Left (negatively skewed)
Data is pushed right, lack of data on left
Univariate Data
Data with one variable
Bivariate Data
Data with two variables
(Discrete or Continuous) the number of classes taken by a college freshman
Discrete
For categorical date, the best graphs to use are...
Pie chart and bar graph
(True/False) A data set is multivariate if it consists only of numeric variables.
False
(True/False) A histogram with a longer upper tail than lower tail is considered negatively skewed.
False
(True/False) The bars of the histogram are centered over the x-values for discrete date.
False
Multimodal Data
More than two modes or high points
Multivariate Data
More than two variables are measured on a single experimental unit.
(Categorical or Numerical) Length
Numerical, continuous
(Categorical or Numerical) Weight
Numerical, continuous
Unimodal Data
One mode or high point
For numerical data, the best graphs to use are...
Scatterplot, Stem-and-leaf plot, Histogram, Time-plot, Cumulative Relative Frequency
(True/False) A frequency distribution is a table that displays frequencies or relative frequencies for categories for values (or intervals of values).
True
(True/False) A time plot is used to show trends or cycles in the data.
True
(True/False) An outlier is an unusually small or large data value.
True
(True/False) Dot plots and stem-and-leaf plots work best for smaller numerical data sets.
True
(True/False) Histograms can be used with either discrete or continuous numeric data.
True
(True/False) In a histogram, the quantity of the square root of the number of observations often gives a rough estimate for an appropriate number of intervals (bars).
True
(True/False) Stem-and-leaf plots can retain the original observations.
True
(True/False) The cumulative relative frequency can be calculated by adding the previous cumulative relative frequency to the relative frequency of the current interval.
True
(True/False) The entire collection of individuals or objects about which information is desired is called the population of interest.
True
(True/False) There should be no spaces between bars in a histogram.
True
Bimodal Data
Two modes or high points
Outlier
Unusually placed point, really far outside the rest of the points
Pie Charts
Use with categorical data and a relatively small number of possible categories