Stat 350 Lab Session
GSI: Yizao Wang
Section 016 Mon 2pm30-4pm MH 444-D
Section 043 Wed 2pm30-4pm MH 444-B
Today’s Agenda
• Final Exam Review
• Final CAOS and Attitudes Survey
• Lab Evaluations
Important Dates
• Today is the last lab of the semester
• HW12 due Monday April 14th before
6pm30, 2237 Chem HW bins
• Graded HW11 & HW12 in 2237 Chem HW
bins, Wed and Thu, April 16th and 17th
• Final exam Thu, April 17th 7pm30-9pm30
Material: all lectures/labs/HWs
Since Exam 2…
• We’ve covered three major topics
– ANOVA
– Regression
– Chi-square (covered this week in lectures)
• Do you know when it is appropriate to use
each?
ANOVA
• Extension of pooled 2-independent
samples t-test
• Do you know how to find an estimate of
the common population variance?
• Do you know when it is appropriate to use
Tukey’s Multiple Comparisons procedure,
and how to interpret this output?
Regression
• Used to find linear relationship between
two quantitative variables
• Do you know how to test if there is a
significant linear relationship?
• Do you know what the assumptions for
this test are, and how to check them?
Suppose we want to explore the relationship
between Exam 1 scores and Exam 2 scores.
Which procedure would be appropriate?
A) ANOVA
B) Regression
C) Chi-square test of independence
A statistics instructor produces this scatterplot and
regression line to see if her students' exam scores can
be predicted from their scores on a standard test of
mathematical ability.
What do the numbers on the vertical axis represent?
A) Statistics exam scores
B) The number of people
earning each exam
score
C) Mathematics ability
scores
The correlation between height and weight for a
certain breed of plant is found to be 0.8.
What proportion of the variability in plant weight
is NOT explained by height?
A)
B)
C)
D)
1-0.8 = 0.2
(0.8)2 = 0.64
1-(0.8) 2 = 0.36
(1-0.8) 2 = 0.04
Suppose we want to compare the average
Exam 2 scores for each of the 4 academic
classes (e.g. Freshman, Sophomore).
Which procedure would be appropriate?
ANOVA
Regression
Chi-square test of independence
Using the ANOVA table, what is an estimate of
the common population variance?
ANOVA
Gain in Weight
Between Groups
Within Groups
Total
300.958
300.958
55.517
55.517
Sum of
Squares
601.916
3331.037
3932.953
df
2
60
62
Mean Square
300.958
55.517
F
55.517
5.421
Sig .
.007
True or False
The ANOVA table below provides evidence
that all of the population means tested are
different from each other.
ANOVA
Gain in Weight
Between Groups
Within Groups
Total
Sum of
Squares
601.916
3331.037
3932.953
df
2
60
62
Mean Square
300.958
55.517
F
5.421
Sig .
.007
Now that the term is (almost) over…
1. Evaluate this lab section: E&E forms
2. Provide current attitudes towards Statistics & clickers:
–
–
–
Ctools Link Lab Info>Stat 350 Final Attitudes
Answer every question and you will receive
1 extra credit point on the final exam
Do not close the webpage saying you submitted your answers
3. Provide current comprehensive knowledge of Statistics:
–
–
–
Ctools Link Lab Info>Stat 350 Final CAOS
Attempt every question AND get at least 50% correct and you will
receive 1 extra credit point on the final
Do not close the webpage saying you submitted your answer
4. When 2&3 finished, raise your hand show me the two
webpages saying you submitted your answers
Now…
• Complete E&E evaluation form
A volunteer to collect the forms for me…
• Complete the altitude and CAOS surveys
Lab Info>Stat 350 Final Attitudes
Lab Info>Stat 350 Final CAOS
• Tell me when you have the two webpages
saying that you submitted your answers
• Thank you for your attendance and good luck on
your final exam