Chapter 1
How do we describe a distribution?
CUSS
Center
Unusual
Shape
Spread
What is the equation used to find z-score
z= (x-mean)/SD
What does LSRL stand for?
Least Squares Regression Line
If individuals are randomly selected out of a population, what type of sample is this?
Simple Random Sample
Design an experiment with the purpose of determining whether drinking a protein shake after a workout would increase muscle gain over a course of 6 months.
Name 3 confounding variables
Name the explanatory variable
Name the response variable
What was the Treatment?
Answers may vary
Name 1 way a graph/chart can be misleading
The scales, width of bars, any other reasonable response
IF EVERY OBSERVATION IN A DATA SET IS MULTIPLIED BY 10, THE ONLY ONE OF THE FOLLOWING THAT IS NOT MULTIPLIED BY 10 IS
(A.) MEAN,
(B.) MEDIAN,
(C.) IQR,
(D.) STANDARD DEVIATION,
(E.) Z-SCORE
E
Which will have a higher correlation?
a) Heights of wives to heights of Husbands
b) Heights of dogs to heights of owners
c) heights of people at age 12 vs their heights at age 18
c
What is a stratified random Sample?
when individuals or units are grouped by a characteristic or strata and a random sample is selected from each of those groups
WHAT IS THE DIFFERENCE BETWEEN A FREQUENCY TABLE AND A RELATIVE FREQUENCY TABLE?
A FREQUENCY TABLE DISPLAYS THE COUNTS AT WHICH SOMETHING HAPPENS, WHILE A RELATIVE FREQUENCY TABLE SHOWS THE PERCENT OF THE TOTAL NUMBER OF TIMES.
THE PROPORTION OF OBSERVATIONS FROM A STANDARD NORMAL DISTRIBUTION WITH VALUES LARGER THAN -0.75 IS
(A.) 0.2266,
(B.) 0.7422,
(C.) 0.7734,
(D.) 0.8023,
(E.) NONE OF THOSE.
C
How do we describe a scatterplot?
FUDS
Form
Unusual
Direction
Strength
list three types of experimental designs
Completely Randomized design
Block Design
Matched Pairs design
IF THE DISTRIBUTION IS SKEWED TO THE RIGHT WITH NO OUTLIERS, WHAT IS THE RELATIONSHIP BETWEEN THE MEAN AND MEDIAN?
MEAN > MEDIAN
Mr. Wilcox spends a full day at Gingerman Raceway testing some new tires on his Honda Civic. For 400 laps, he records his laptime in minutes. At the end of the day, he plots the distribution of times and realizes that it follows an approximately normal distribution with a mean of 1.84 and a standard deviation of .07.
What proportion of his lap times are between 1.74 minutes and 1.87 minutes?
59% or .59
What does r=-.86 represent?
a strong negative correlation
list 3 possible problems with surveys
undercoverage
nonresponse bias
response bias
Name 3 key features of a box plot
title, scale, 1st Q, Median, 3rd Q, Min, Max, outliers
COMPLETELY LABEL THE NORMAL PROBABILITY MODEL (ASSUMING THE MEAN IS 32 AND THE STANDARD DEVIATION IS 4).
-----20----24----28----32----36----40----44----
N(32,4)
*Must also have curve drawn*
the correlation between number of seagulls and the temperature has an r^2 value of .89
Seagulls are the response variable
Temperature is the explanatory variable
Interpret r^2
89% of the variation between the numbers of seagulls can be represented by the temperature
Design an experiment with the purpose of determining whether drinking a protein shake after a workout would increase muscle gain over a course of 6 months.
Answers may vary