Stats 330 Exam 1 Feb 20

Question 1

Statistics

Answer 1

a collection of methods for planning experiments, obtaining data, and then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on the data.

Question 2

Population

Answer 2

the complete collection of all elements to be measured

Question 3

Sample

Answer 3

a sub collection of elements drawn from a population

Question 4

Statistic

Answer 4

a numerical measurement describing some characteristic of a sample

Question 5

Quantitative Data

Answer 5

consists of numbers representing counts or measurements

Question 6

Qualitative Data

Answer 6

aka categorical. can be separated into diff categories that are distinguished by some nonnumeric characteristic

Question 7

variable

Answer 7

a characteristic or attribute that can assume different values

Question 8

random variables

Answer 8

variables whose values are determined by chance

Question 9

discrete data

Answer 9

result from either a finite number of possible values or a countable number of possible values

Question 10

continuous data

Answer 10

result from infinitely many possible values that can be associated w/points on a continuous scale in such a way that there are no gaps or interruptions

Question 11

Sampling Error

Answer 11

the difference between a sample result and the true population result

Question 12

Frequency Table

Answer 12

lists categories or classes of scores, along with counts (or frequencies) of the number of scores that fall into each category

Question 13

Class Width

Answer 13

Range/ # of classes

Question 14

Cumulative Frequency

Answer 14

the sum of the frequencies for that class and all previous classes

Question 15

Relative Frequency

Answer 15

Class Frequency/ sum of all frequencies

Question 16

Stem and Leaf Plot

Answer 16

Data is sorted according to a pattern that reveals the distribution (shape), also can see original data set.

Question 17

Mean

Answer 17

The sum of all the data values divided by the total number of data values

Question 18

Median

Answer 18

The middle value when data are arranged in numerical order.

Question 19

Mode

Answer 19

The value in a data set that occurs most frequently

Question 20

Skewed Data

Answer 20

Data that is not symmetric and extends more to one side than the other.

Question 21

Skewed Left

Answer 21

Mean to left of median (Mean < Median)

Question 22

Skewed Right

Answer 22

Mean to right of median (Mean > Median)

Question 23

Symmetrical Distribution

Answer 23

Mean and Median are equal

Question 24

Variation

Answer 24

the amount that scores vary among themselves

Question 25

Variance

Answer 25

average of squares of the distance each value is from the mean

Question 26

Standard Deviation

Answer 26

square root of the variance