Data Basics
The entire group of individuals to be studied is called...
Population
Gender
Qualitative, nominal
What are the three necessary attributes to make a study experimental?
Random assignment, groups, and "treatment" options
True or False? A bimodal distribution will always be symmetrical.
False
Which visual summary allows us to see shape frequencies?
Histogram
Type of Sample: Choosing the first 10 trees that you see in the area...
Convenience sampling
The time it takes to finish a 5K rounded to the nearest minute...
Quantitative, discrete
researchers recruited 72 healthy, physically active men ages 18-35 and divided them into three groups. During the study, each participant drank still water (Highland Spring) and three beverages that were randomly picked for them. By tracking the men's urine output after each beverage, the scientists could assign a beverage hydration index, or BHI, to each drink. Experimental or observational?
Experimental
Measures of Center, or numerical summaries, include...
Mean, median, and mode
Median and IQR
Type of Sample: Numbering the trees in the area, placing all the numbers in a bag, then choosing 10 tree numbers from the bag...
Simple random sampling
Carnival Cruise Lines assigns cruise goers into "Blue", "Red", "Gold", "Platinum", and "Diamond" depending on how many nights they've stayed on a cruise from that line...
Qualitative, ordinal
Harvey is a TA for a statistics class and decides to send out a survey asking students if they attended office hours. Harvey randomly chooses one of the two statistics classes and asks students sitting in the front row to fill the survey out. Harvey concludes that students who succeeded in the class attended office hours. Can the study be generalized to all of the statistics classes?
No
We calculate the relative frequency by...
dividing the frequency of observation by total observations
If Q1 = 24, Median = 32, Q3 = 55, what is the IQR?
31
Stratified sampling
Access the LEAPdata by typing the following code into your console in RStudio: LEAPdata<-read.csv("https://aub.ie/LEAPdata"). What type of variable is Age.months?
Quantitative, continuous
Typically, a dog would be given several "specimens", one of which corresponded to a patient who had tested positive for COVID. The dog would be trained to sniff the specimens and then sit down next to the COVID specimen. The dog's performance would be tested over several trials, with the location of the COVID specimen randomly determined each time. Type of study?
Observational
Measures of Spread include...
Range, standard deviation, variance, and Interquartile range
If a boxplot/graph is left skewed, how do the mean and median relate to each other?
Mean < median
Consider the letters: A, B, C, D, E, F, G. What are the chances that any particular sample of two letters will be the one selected?
1/21
Using the LEAP data, what variable is Overall.V60.outcome?
LEAPdata<-read.csv("https://aub.ie/LEAPdata")
Qualitative, nominal
Typically, a dog would be given several "specimens", one of which corresponded to a patient who had tested positive for COVID. The dog would be trained to sniff the specimens and then sit down next to the COVID specimen. The dog's performance would be tested over several trials, with the location of the COVID specimen randomly determined each time. What is the response variable?
The dog's reaction.
Use RStudio to calculate the mean, median, and summary, specifically Q1 and Q3 of the following list: 322, 270, 260, 266, 257, 260, 267
Mean: 271.71
Median: 266
Q1: 260.0
Q3: 268.5
T/F: All quartiles of a boxplot are equal.
True