Statistics 528 - Lecture 5
Section 1.3 cont.
Normal Distributions
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All normal distributions have the same shape - symmetric, unimodal,
bell-shaped
The mean (µ) and standard deviation (σ) completely specify a normal
density curve.
The mean (µ) is th
Statistics 528 - Lecture 5
Section 1.3 cont.
Normal Distributions
•
•
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All normal distributions have the same shape - symmetric, unimodal,
bell-shaped
The mean (µ) and standard deviation (σ) completely specify a normal
density curve.
The mean (µ) is the
Statistics 528 - Lecture 4
Section 1.3
Relative Frequency of Scores Less Than or Equal to 6.0
Density Curves
Mathematical model for the distribution of a variable
Alternative to graphical and numerical summaries
Idealized description - histogram of the da
Statistics 528 - Lecture 4
Section 1.3
Density Curves
Mathematical model for the distribution of a variable
Alternative to graphical and numerical summaries
Idealized description - histogram of the data is not exactly the same as
the curve
Compact represe
Statistics 528 - Lecture 3
Section 1.1/1.2
Graphical and Numerical Summaries of Data
Modes
Shape of a Distribution
Question: Does the distribution have one or several major peaks?
Modes
Symmetric vs. Skewed
Outliers
A distribution with one major peak i
Statistics 528 - Lecture 3
Section 1.1/1.2
Graphical and Numerical Summaries of Data
Shape of a Distribution
Modes
Symmetric vs. Skewed
Outliers
Measures of the Center
mean
median
Measures of Spread
IQR
standard deviation
Choosing Summaries of Dist
Statistics 528 - Lecture 2
Section 1.1
Displaying Distributions with Graphs
• Issue: How do we examine and describe the main features
of a data set?
• We do exploratory data analysis. It involves
– examining each variable
– examining relationships between
Statistics 528 - Lecture 1
Statistics 528
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Introduction to the Course
Class Survey
Syllabus
Course Website
Overview
Chapter 1: Introduction
Statistics 528 - Lecture 1
Prof. Kate Calder
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1
Categorical variables place individuals into one or
Statistics 528: Homework 8
Due Friday, March 12
1. IPS Section 6.1, exercises 6.7, 6.10, 6.16, 6.22.
For exercise 6.7, use Minitab to compute the sample mean. Then compute the
confidence intervals two ways: i) by hand and ii) using Minitab.
2. IPS Section
Statistics 528 – Homework 7 Solutions
5.2
(a) No, not a fixed number of trials.
(b) Yes, we choose a sample of fixed size and since 100 persons are chosen at random,
each person in the sample has the same probability of opposing the death penalty ran on
s
Statistics 528 – Homework 6 Solutions
4.10
(a) The sample space would be {female, male}.
(b) The sample space would be {6, 7, …, 20}.
(c) The sample space would be the interval [2.5, 6]/min.
(d) For living human beings, heart rate is probably in the range
Statistics 528 – Homework 5 Solutions
Corrected Version
3.8
(a) In the study, no deliberate assignment of the anesthetics to the patients was done
in order to see the effect of the anesthetics on death rates.
(b) Type of surgery, patient allergy to certai
Statistics 528 – Homework 4 Solutions
2.40
(a)
Absorbance
200
100
0
0
1000
2000
Nitrates
Minitab gives the correlation 1.0 (in fact, .99994). Note that it is rounded up.
So, recalibration would not be necessary.
(b) The equation of the least squares line
Statistics 528 - HW3 Solutions
2.1
(a) Grade would be response and time of study would be explanatory.
(b) Relationship.
(c) Rain would be explanatory and yield would be response.
(d) Relationship.
(e) Income would be explanatory and education would be re
Statistics 528: Homework 3
Due Friday, January 30
1. IPS Section 2.1, exercises 2.1, 2.4, 2.8, 2.12
Making a scatterplot in MINITAB:
Select Graph-Plot and then choose the variable for the X (horizontal) axis and
the Y (vertical) axis. For exercise 2.12, y
Statistics 528: Homework 2 Solutions
1.41 There are several gaps in the data, as can be seen from the histogram.
Minitab Result:
Min
2508
Q1
13278
Med
17022
Q3
23568
Max
26241
Q1
13385
Med
17022.5
Q3
23552
Max
26241
Manual Result:
Min
2508
We cannot find
Statistics 528: Homework 2
Due Friday, January 23
1. IPS Section 1.2 exercises 1.41, 1.45, 1.50, 1.58, 1.72
2. IPS Section 1.3 exercises 1.78, 1.86, 1.88, 1.98, 1.112, 1.140
Problem 1.140 is a bit more open-ended than other problems in the text.
The idea
Stat 528 - Homework 1 Solutions
1.2
The individuals of the set of data are the students: Advani, Barton, etc.
The data contain the values of students, major, points and grade. So the variables are
Major, Points and Grade. Major is categorical. Points is q
Statistics 528: Homework 1
Due Wednesday, January 14
1. Getting Started with MINITAB: Work through MINITAB Handout 1. Using the
alfalfa data, carry out the following.
a) Make boxplots of
, split by
.
b) Make dot plots of
, split by
.
c) On the basis of yo
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Statistics 528: Minitab Handout 1
Throughout the STAT 528-530 sequence, you will be asked to perform numerous statistical
calculations with the aid of the Minitab software package. This handout will get you
started with Minitab. As the course progresses,
Name:_
Statistics 528 Midterm Solutions
Winter 2004
INSTRUCTIONS
Show your work on all problems to receive full credit.
Problem 1 (15 points)
In a statistics class with 136 students, the professor recorded how much money each
student had in his or her wal