Statistics Midterm Review 1) What is the difference between an observational stu
ID: 3350290 • Letter: S
Question
Statistics Midterm Review 1) What is the difference between an observational study and an experiment? or lee thre ar overalrh date of birth, weight, address, etc. ) Of the variables listed, which are quantitative? Of the variables listed, which are categorical (qualitative)? 3) What is the difference between a response variable and an explanatory variable? 4) In the situation where Mr. Burns is testing to see whether a new fertilizer will impact plant growth, which variable is the response and which is the explanatory? Chapter 2 1) Shown to the right is a stem and leaf Baseball Throwing Distances in Feet plot for baseball throwing distances. Take special notice of the key which specifies that 312 represents 3.2 NOT 32 Stem Leaves 035 126 0234 03678 125 3 4 ) State the five number summary ii) Identify any outliers mathematically 10 25 Key: 3 2 3.2 feet ili) Construct a box and whiskerplot iv) Calculate mean and standard deviation from the stem and leaf plot.Explanation / Answer
Chapter 1:
(1) In an observational study, investigators observe subjects and measure variables of interest without applying treatments to the subjects. The treatment that is administered to each subject is not in the control of the investigator.
In an experiment, an investigator applies treatments to subjects, who, if required, are divided into groups and then the variables of interest are measured.
(2) Quantitative - age, date of birth, weight.
Qualitative - eye color, hair color, address.
(3) In case of an explanatory variables,it is manipulated in an experiment in order to observe the effect on a dependent variable, which is called a response variable. It explains the changes in the response variable.
In case of a response variable, it is the focus of a question of a study or experiment. It is our variable of interest in an experiment.
(4) Response variable -> plant growth
Explanatory variable -> amount of new fertilizer administered