Exam 1 Flashcards
Random irregularity in real life data is ______.
Random irregularity in real life data is Noise/Stochasticity
Which of the following is NOT a measure of the center of data?
Mean
Median
Mode
Sum of Squares
Sum of Squares
Describe the shape of this distribution
Positively Skewed
Right Skewed
Follow direction of tail
A null hypothesis needs to be ______.
Provable
Falsifiable
Accepted
Falsifiable
This is an example of a _____ distribution.
Normal
Negatively Skewed
Symmetrical
Positively Skewed
Negatively Skewed
Solve the following summation given this data:
20 16 14 15 19
168
We can either multiply each number by 2 before adding them.
40+32+28+30+38 = 168
Or we can add them up and multiply the sum by 2
2(20+16+14+15+19) = 2(84) = 168
Name a common measure of dispersion (more than one correct answer)
Range
Variance
Standard Deviation
Average Absolute Deviation
You gather the following data on GMU students:
Grade Level
GPA
Major
GPA is what kind of data?
Discrete
Ordinal
Nominal
Continuous
Continuous
Grade Level is what kind of data?
Discrete
Ordinal
Nominal
Continuous
Ordinal
What does mean describe? (Possible answer choices center, spread/dispersion)
Center
Variance
Spread/dispersion
Average absolute deviation
Spread/dispersion
Median
Center
(N+1)/2 = median data point. Example in a data set of 1,3,4,6,7,8,9
N=7
Median = (7+1)/2 = 4th data point = 6
Range
Spread/dispersion
Max-Min
Mode
Center
Most frequently occurring number. Distributions can be unimodal, bimodal, or multimodal
Standard deviation
Spread/dispersion
SDev = (x-mean)^2
(N-1)
20
1+1
1+2
1+3
1+4
1+5
or (5x1)+(1+2+3+4+5)
60
= 2(1+3) +2(2+3)+2(3+3)+2(4+3)+2(5+3)
What type of data is blood type?
Nominal
What type of data is income level?
Ordinal
What type of data is inventory of supplies?
Discrete
What type of data is hair color?
Nominal
What type of data is temperature?
Continuous
What type of data is the number of students per grade level?
Discrete
What type of data is continuous?
Monthly expenses
What type of data is continuous?
Monthly expenses
1/15
Area of the entire probability graph will have to equal 1.0
15 * x = 1
x=1/15=0.06667
4*k = probability that student walks 3-7 miles
4*0.06667 = 0.26667
What is Poisson distribution used to model? Which parameter(s) do you need?
Rare, independent, random occurrences when the probability of occurring is small
Population mean
it’s appropriate for modeling counts of observations per unit
Which distribution would be expected to have the largest population mean and be most accurate to represent the desired outcome?
D
