Semester Review Stat Lab

Question 1

(1.2) Parameter

Answer 1

Describes some characteristic of a population (a population of x…)

Question 2

(1.2) Statistic

Answer 2

Describes some character of a sample ( x of x amt, percentages, means)

Question 3

(1.2) Discrete

Answer 3

Countable; only takes on specific values (# of t shirt sizes)

Question 4

(1.2) Continuous

Answer 4

Infinite; can take on many values (weight, area, mass)

Question 5

(1.2) Nominal

Answer 5

Categories, names, and labels only; can’t be arranged in order (ex: music genres, gender, etc.)

Question 6

(1.2) Ordinal

Answer 6

can be arranged in order; differences in data can’t be determined or are meaningless (ex: movie ratings, letter grades, rankings)

Question 7

(1.2) Interval

Answer 7

like ordinal, but difference btwn data value matters; doesn’t have natural zero starting point (not necessary the absence of any data) (ex: temperature, years, etc.)

Question 8

(1.2) Ratio

Answer 8

like interval, but there is a natural zero starting point; differences & ratios matter (ex: money, height, age)

Question 9

(2.1) Outliers

Answer 9

Sample values that lie very far away from the majority of the other sample values

Question 10

(2.1) Distribution Shape

Answer 10

Normal = bell-shaped
Longer right tail = data skewed to right
Longer left tail = data skewed to left

Question 11

(2.1) Outlier on histogram…

Answer 11

… will appear as a bar far from all the others w/ a height corresponding to 1

Question 12

(2.1) Histogram

Answer 12

Graph w/ equal-width bars next to each other
(horizontal = quantitative classes; vertical = frequencies)
(find n by adding bars together)

Question 13

(3.1) Mode

Answer 13

Measure of center w/ value that occurs with greatest frequency

Question 14

(3.1) Median

Answer 14

middle value when original data values are in increasing / decreasing order; resistant

Question 15

(3.2) Standard Deviation Properties

Answer 15

(1) unit of SD are same as units of original data
(2) measure of variation of all data values from the mean
(3) never negative

Question 16

Variance

Answer 16

Square of the standard deviation

Question 17

(3.3) Z-Score Properties

Answer 17

• no units of measurement (in., cm.)
• above of below mean
• significantly high or low (2 <p< -2)
• Greater than mean = +; Less = -

Question 18

(3.3) Range Rule of Thumb

Answer 18

Value (x) -/+ (1,2,3…) standard deviation
- significantly high (+) or low (-)

Question 19

(3.3) Z-Score

Answer 19

How many standards deviations away it is from the mean (round to two decimal places); x - x̄/SD

Question 20

(3.1) Mean

Answer 20

sum of data values / # of values; non-resistant

Question 21

(3.1) midrange

Answer 21

Max - min value /2

Question 22

(3.3) Percentiles

Answer 22

kth percentile being used (k = 25) (ex: 66th percentile = .66 to its left, or 66%)

Question 23

(4.1) Relative Freq Approx of Probability

Answer 23

P(a) = # of ways A occurred (x) / # of times experiment repeated (n)

Question 24

(4.1) Classic Probability

Answer 24

P(a) = # of way A can occur (s) / # of different simple events (n)

Question 25

(4.1) Signicance Value of Probabilties is…

Answer 25

greater (>) or less (<) than 0.5

Question 26

(5.1) Probability Distribution Properties

Answer 26

(1) btwn 0 and 1 inclusive
(2) numerical, NOT categorical, x values
(3) sum of probabilities = 1

Question 27

(6.1) NORMAL distribution

Answer 27

• bell-shaped
• close to line
• no other shape than line
• symmetric
• centered around mean

Question 28

(6.1) UNIFORM distribution

Answer 28

• rectangle-shaped
• close to line
• another shape than line

Question 29

(6.1) SKEWED distribution

Answer 29

• has tail
• not close to line

Question 30

(6.1) standard normal probability distribution

Answer 30

Mean = 0 and standard deviation = 1

Question 31

(6.1) Finding probabilities associated w/ distributions that are STANDARD NORMAL distributions is equivalent to..

Answer 31

Finding the area of the shaded region representing that probability

Question 32

(6.2) Separating Values on Normal Distribution Graphs

Answer 32

Top % = right side of horizontal scale
Bottom % = left side of horizontal scale

Question 33

(6.3) Negative Z-Scores

Answer 33

A z-score corresponding to a value located to the left of the mean

Question 34

(7.1) Point estimate

Answer 34

Single value used to approximate a population parameter

Question 35

(7.2, sheet) best point estimate of population MEAN (μ)?

Answer 35

Sample mean (x̄)

Question 36

(7.2, sheet) best point estimate of population PROPORTION (p)

Answer 36

Sample proportion (p̂)

Question 37

(7.2) Interpreting A Confidence Interval

Answer 37

P: 99% CI of 4.1 < μ < 5.6?
A: “We are 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of μ.”

Question 38

(8.1) Concluding H1 Claims in Hypothesis Testing

Answer 38

DOESN’T include equality = support

Question 39

(8.1) Concluding H0 Claims in Hypothesis Testing

Answer 39

DOES Include equality = warrant rejection

Question 40

Decision Mantra of P-value & Alpha

Answer 40

“P’s high? Null will fly.
P’s low? Null’s gotta go.”

Question 41

(8.1) P-value

Answer 41

Probability of getting a value of the t-stat that’s at least as extreme as the one representing the sample data (assuming H0 is true)

Question 42

(8.1) Hypothesis Test

Answer 42

A procedure for testing a claim about a property of a population

Question 43

(8.1) Null hypothesis

Answer 43

A statement that the value of the population parameter is equal to some claimed value

Question 44

(9.2) dependent sample

Answer 44

subjects in one group do provide information about subjects in other groups

Question 45

(9.2) independent sample

Answer 45

Randomly selected samples thats observations do not depend on the values other observations

Question 46

(12.1) One Way Analysis of Variance (ANOVA)

Answer 46

Used for hypothesis test finding if 3+ population means are equal; uses F distribution