Lab 3 Practice: Summarizing and Visualizing Data
Practice
1. Import the ADNI.txt data set. How many observations are there?
There are 276 observations in the ADNI.txt data set.
2. For each variable in the data set, describe what the variable represents in
QTM 100 Spring 2016
Midterm 2 Review
Confidence Intervals - (Lectures 12, revisited through many lectures)
A point estimate is a single number that is our best guess for the parameter.
An interval estimate is an interval of numbers within which the para
Data
Steps 1-4
Step 5
Step 6
Step 7
HW
Clicker
In 2000, research indicated that the proportion of Americans who
were vegetarian was 0.15. A recent random sample of 1500
Americans shows that the proportion of Americans who are
vegetarian is 0.17. We would
Data
6= variances
Variances =?
= variances
HW
First Clicker
Data
= variances
HW
Paired t-test
A Type II error is possible
A. when we reject H0
B. when we fail to reject H0
C. either
I
D. neither
I
QTM 100: Lecture 18
Data
6= variances
Variances =?
1 / 36
Data
Hypothesis test about a mean
Step 5
Step 6
Step 7
Data
Hypothesis test about a mean
Step 5
Step 6
Step 7
First Clicker
A 95% confidence interval for the true proportion of US citizens
who are opposed to issuing traffic tickets from traffic cameras is
p-values
1-sided or 2-sided Ha ?
CI vs Test
Testing Considerations
Clicker
p-values
1-sided or 2-sided Ha ?
CI vs Test
Testing Considerations
Summary
t=
x 0
p
s/ n
100(1
Assume x, 0 , and s are fixed, what would happen to the test
statistic and p-value as
CIs for
t distribution
Hypothesis Testing
CIs for
t distribution
Hypothesis Testing
Clicker
Lecture 13: Confidence Interval for a Mean and
Intro to Hypothesis Testing
Find the value of z used to construct a 80% confidence
interval?
A. 0.79
B. 0.84
Zhiyu
Data
Test for d
CI for d
Clicker
Data
Test for d
CI for d
Neyman and Pearson (1933)
Neyman J, Pearson E. On the problem of the most efficient tests of statistical
hypotheses. Philosophical Transactions of the Royal Society, Series A. 1933;231:289-337.
Sup
2204329
LE 1
Table 1: Possible Factors Impacting Academic Honesty and Prohibited Cellphone
Use During Exams
Overall
(n=277)
Variable
Identified Gender
(Female)
(Male)
Identified GPA
Identified Race
(Caucasian)
(African American)
(Asian)
(Other)
Hours of E
Midterm 1 Review
Intro to Stats (Lecture 2)
What is the field/discipline/science of statistics?
What is the dierence between anecdotal evidence and more formal evidence?
Three main components of statistic: design, description, inference
population vs samp
2204329
Lab Practice 3
LE 1
1.
Lab 3 Practice
Import the ADNI.txt data set. How many observations are there?
1
- There are 276 observations.
1
- R Code: dim(ADNI)
2 dim(ADNI)
3 [1] 276 8
4
2.
- Comment: The dim(ADNI) command was used to identify the dimen
2204329
LE 1
Lab 4 Practice
1. Compare the distribution of lifespan among the five experimental groups of fruitflies.
(a) Produce an appropriate figure to compare the distribution of lifespan among the
five experimental groups of fruitflies. What figure d
2204329
LE 1
Lab 5 Practice
1. Examine the population distribution of days drink.
(a) Describe the shape of the population distribution.
The shape is right skewed.
R Code: > str(yrbss2013$days_drink)
int [1:8482] 30 1 0 0 0 1 0 0 0 0 .
> summary(yrbss2013
QTM Lab 4 Practice
Student ID: 2251202
1. Compare the distribution of lifespan among the five experimental groups of fruitflies.
(a) Produce an appropriate figure to compare the distribution of lifespan among the five experimental groups of
fruitflies. Wh
Lab 9 Practice
Student ID: 2251202
11 November 2016
1. Explore the lead blood levels of the children in 1972 (Ld72) and 1973 (Ld73).
(a) Are these measurements paired, or do they represent two indpendent groups. Why?
The measurements are paired because th
QTM 100 Lab 7
Student ID: 2251202
28 October 2016
1. Submit the following code to create a new data set called no dups which eliminates multiple course
evaluations of the same professor. This will create a data set that contains each professor only one ti
Homework 6
Shaan
10/24/2016
library("dplyr",
lib.loc="/Library/Frameworks/R.framework/Versions/3.3/Resources/library")
#
# Attaching package: 'dplyr'
# The following objects are masked from 'package:stats':
#
#
filter, lag
# The following objects are mask
Untitled
Shaan
9/29/2016
gss <- read.csv("~/Desktop/Classes/Fall 2016/QTM 110/gss.csv")
library(ggplot2)
library(dplyr)
#
# Attaching package: 'dplyr'
# The following objects are masked from 'package:stats':
#
#
filter, lag
# The following objects are mas
Homework 10
Shaan
11/29/2016
library("dplyr",
lib.loc="/Library/Frameworks/R.framework/Versions/3.3/Resources/library")
#
# Attaching package: 'dplyr'
# The following objects are masked from 'package:stats':
#
#
filter, lag
# The following objects are mas
Lab 6 Practice: Data cleaning and manipulation
Background
UFO abductees are individuals who believe they have been kidnapped by extra-terrestrials. Many abductees believe that extraterrestrials have the ability to erase memories of the abduction. In the 1
Lab 5 Practice
Student ID: 2251202
For this lab, you will need to import the yrbss2013.csv data set, as well as submit the files contained within
SamplingFunctions.R. For questions 1-5 you will explore repeated samples from days drink, and for questions 6