Types of Data
Measures of Center & Variation
Histograms & Frequency Distributions
Miscellaneous
Measures of Relative Standing
Types of studies and Sampling techniques
100
Identify the following as nominal, interval, ordinal, or ratio:
Political affiliation
Nominal
100
Give the symbol for population mean
mu
100
What would be an appropriate lower class limit to use?
90 or 95
100
Give the symbol for population variance
sigma^2
100
Which score indicates a score that is further from the mean (in either direction). Choose a, b, or c
a. A score of 3.2 on a test with a mean of 4.6 and a standard deviation of 1.5
b. A score of 630 on a test with a mean of 800 and a standard deviation of 200
c. A score of 43 on a test with a mean of 50 and a standard deviation of 5.
a. z = -0.93
b. z = -0.85
c. z = -1.40
C
100
Identify as observational or experimental
A researcher stood at a busy intersection and recorded whether children were buckled into safety seats
Observational study
200
Identify the following as nominal, interval, ordinal, or ratio
Weights of participants on a new diet
Ratio
200
What are the 4 measures of center?
Mean, Median, Mode & Midrange
200
What would be an appropriate class width to use to create a frequency distribution with 6 classes?
CW =
(max - min)/(# classes)
(129 - 95)/6 = 5.666666
CW = 6
200
Find the percentile that corresponds with the data value of 113.
(23/40)(100) = 57.5
P58
200
Find P20
(20/100)(40) = 8
(102 + 103)/2 = 102.5
200
Identify as observational or experimental.
A study was conducted in which one group was given a Vitamin D tablet each day for 1 year. The other group was given a placebo tablet. A record was kept of the number of illnesses each person had and it was compared at the end of the year.
Experimental study
300
Identify the following as nominal, ordinal, interval, or ratio
Years that presidents were elected
Interval
300
If the standard deviation is 7 cm, find the variance. Include appropriate units.
49 cm
300
What are the class boundaries of the 4th class?
112.5 - 118.5
300
Identify the sample and the population
A random sample was conducted of parents in the Union County School system. Fifty parents were randomly selected to complete the survey.
Sample: 50 parents
Population: All parents
300
If the final exam has a mean score of 83 and a standard deviation of 3.2. Find the corresponding z score for a score of 94 on the exam. Is this considered significantly high?
z = (94-83)/3.2=3.44
300
Identify the following type of sample as random, systematic, stratified, or cluster
Every 50th person that came through the door at the grand opening was surveyed to see how they learned about the grand opening sale.
Systematic
400
Identify as a discrete or continuous variable
Number of textbooks purchased by Wingate University students
Discrete
400
Find the mean of the frequency distribution.
75.5
400
What is the class midpoint of the 3rd class?
(107 + 112)/2 = 109.5
400
Recently Fox News had a call-in survey asking who they are voting for in this year's presidential election. Would the results be representative of all US citizens? Would the results be representative of FOX viewers?
No; No; Voluntary Response
400
If the average age of workers at a company is normally distributed with a mean of 32 years old and a standard deviation of 5 years. Using the Empirical Rule approximately what percentage of workers are ages 22 to 42?
95%
400
Identify the following type of sample as random, systematic, stratified, or cluster
At Wingate Elementary school, the principal wanted to survey parents of students. He randomly chose 15 parents per grade level and asked them to complete a survey.
Stratified
500
Identify as a discrete or continuous variable
Body temperatures of children at the doctor's office
Continuous
500
A student earned grades of C, A, B, and A. Those courses had these corresponding numbers of credit hours: 3, 6, 2, and 6. The grading system assigns quality points to letter grades as follows: A = 4, B = 3, C = 2, D=1, F=0. Compute the grade point average (GPA) and round to two decimal places.
3.53
500
What is the relative frequency of the 1st class?
6/10 = 0.15 or 15%
500
If a data set has Q1 = 75 and Q3= 120, would 150 be considered an outlier?
No
Outliers > 120 + 1.5(IQR)
Outliers > 120 + 1.5(120 -75)
Outliers > 187.5
500
If the mean triglyceride level is 150 with a standard deviation of 12.8, and the mean cholesterol level is 197 with a standard deviation of 13.4, determine which of the following is a relatively "better" level:
A triglyceride level of 165
A cholesterol level of 215
Triglyceride: z = 1.17
Cholesterol: z = 1.34
Triglyceride is better
500
Identify the following type of sample as random, systematic, stratified, or cluster
The North Carolina school system wanted to study the preparedness of schools to deal with campus violence. Twenty N.C. schools were randomly selected and all faculty at those schools were asked to complete a survey.
Cluster