Exam 1- Ch 1, 2, 3, & 6

Question 0

Statistics that collects, organizes, and presents the data

Answer 0

Descriptive Statistics

Question 1

The methodology of extracting useful information from a data set

Answer 1

Statistics

Question 2

Statistics that draws conclusions about a population based on sample data from that population

Answer 2

Inferential statistics

Question 3

Consists of all items of interest

Answer 3

Population

Question 4

A subset of the population

Answer 4

Sample

Question 5

Data collected by recording a characteristic of many subjects at the same point in time, without regard to differences in time

Answer 5

Cross-sectional data

Question 6

Data collected by recording a characteristic of a subject over several time periods

Answer 6

Time series data

Question 7

Two types of variables

Answer 7

Qualitative and quantitative

Question 8

This quantitative variable assumes a countable number of distinct values

Answer 8

Discrete

Ex: number of children, points scored in a game

Question 9

Quantitative variable that can assume an infinite number of values within some interval

Answer 9

Continuous variable

Ex: weight, height, investment return

Question 10

Scales of measure

Answer 10

Nominal
Ordinal
Interval
Ratio

Question 11

The least sophisticated level of measurement

Data are simply categories for grouping the data

Answer 11

Nominal scale

Question 12

Data may be categorized and ranked with respect to some characteristic or trait

Differences between categories are meaningless because the actual numbers used may be arbitrary

Answer 12

Ordinal scale

Question 13

Data may be categorized and ranked with respect to some characteristic.

No “absolute 0”

Answer 13

Interval scale

Question 14

Strongest level of measurement

There IS an “absolute 0”

Answer 14

Ratio scale

Question 15

The characteristic of an observation or individual

Answer 15

Variable

Question 16

The values associated with a variable

Answer 16

Data

Question 17

By dividing each category’s frequency by the sample size, you get what?

Answer 17

Relative frequency

Question 18

A segmented circle whose segments portray the relative frequencies of the categories of some qualitative variable

Answer 18

Pie chart

Question 19

Depicts the frequency or the relative frequency for each category of the qualitative data as a bar rising vertically from the horizontal axis

Answer 19

Bar chart

Question 20

Identifies the proportion or fraction of values that fall into each class

Answer 20

Relative frequency distribution

Question 21

Gives the proportion or fraction of values that fall below the upper limit of each class

Answer 21

Cumulative relative frequency distribution

Question 22

A visual representation of a frequency or a relative frequency distribution

Answer 22

Histogram

Question 23

Shape of distribution

Answer 23

Typically symmetric or skewed

Question 24

Shape of distribution that is a mirror image on both sides of its center

Answer 24

Symmetric

Question 25

Shape of distribution where data forms a long, narrow tail to the right

Answer 25

Positively skewed

Question 26

Shape of distribution where data forms a long, narrow tail to the left

Answer 26

Negatively skewed

Question 27

A visual representation of a frequency or a relative frequency distribution

Answer 27

Polygon

Question 28

A visual representation of a cumulative frequency or a cumulative relative frequency distribution

Answer 28

Ogive

Question 29

Provides a visual display of quantitative data, it gives an overall picture of the data’s center and variability

Answer 29

Stem and leaf diagram

Question 30

The primary measure of central location

Answer 30

Arithmetic mean

Question 31

Another measure of central location that is not affected by outliers

Answer 31

Median

Question 32

Another measure of central location, by the most frequently occurring value in a data set

Answer 32

Mode

Question 33

Measures of dispersion include:

Answer 33

Range
Mean Absolute Deviation
Variance and Standard Deviation
Coefficient of Variation

Question 34

? = maximum value - minimum value

Answer 34

? = range

Question 35

An average of the absolute difference of each observation from the mean

Answer 35

Mean absolute deviation (MAD)

Question 36

This adjusts for differences in the magnitudes of the means

Answer 36

Coefficient of variation

Question 37

The manner in which data are distributed

Answer 37

Shape

Question 38

A measure of symmetry of the lack of it

Answer 38

Soreness

Question 39

A measure of whether data are peaked of flat relative to a normal distribution

Answer 39

Kurtosis

Question 40

For any data set, the proportion of observations that lie within k standard deviations from the mean is at least 1-1/k^2, where k is any number greater than 1

Answer 40

Chebyshev’s Theorem

Question 41

Empirical Rule

Answer 41

Empirical Rule

Question 42

Describes the likelihood that x assumes a value within a given interval

Answer 42

Probability density function

Question 43

For any value x of the random variable X, the cumulative distribution function f(x) is computed as f(x) = P(X _< x)

Answer 43

Cumulative density function

Question 44

Describes a random variable that has an equally likely chance of assuming a value within a specified range

Answer 44

Continuous uniform distribution

Question 45

Closely approximates the probability distribution of a wide range of random variables

Answer 45

Normal distribution

Question 46

Characteristics of normal distribution

Answer 46

Symmetric- about its mean

Asymptotic- that is, the tails get closer and closer to the horizontal axis, but never touch it

Question 47

Normal distribution is completely described by two parameters

Answer 47

u is the population mean which describes the central location of the distribution

o^2 is the population variance which describes the dispersion of the distribution

Question 48

A special case of the normal distribution

Answer 48

Standard normal (z) distribution

Question 49

Gives the cumulative probabilities P(Z _< z) for positive and negative values of z

Answer 49

Standard normal table (Z table)