Stat 252
September 29th, 2017
HW 3
1. It is recommended to exercise about 4 hours per week. However, I believe Cal Poly to be a
relatively fit campus so I believe that Cal Poly students, on average, w
Stat 252
September 26th, 2017
One Sample Mean CI
Recall the CLT for a Sample Mean that states:
x ~ N(,
n )
Our conditions for the confidence interval and hypothesis testing of one sample means will be
Stat 252
October 6th, 2017
Practice Exam 1
1. True or False Questions. Circle T for True and F for False.
a. A 95% confidence interval of (135, 140) means that 95% of samples will produce sample
means
Stat 252
October 24th, 2017
Correlation & Least Squares Regression
Two Quantitative Variables
Scatterplot
Graphical display between two quantitative variables
Association (Relationship)
Form, Directio
Stat 252
October 12th, 2017
Chi-Square Goodness-of-Fit
Example: The MARS company makes the popular candy Skittles. MARS claims that in each bag, the five
colors (red, orange, yellow, green, purple) ar
Stat 252
October 20th, 2017
ANOVA: Multiple Comparisons
Why not just do several two sample t-tests for the difference in population means all at the same
significance level (i.e. all = 0.05)?
= P(_ Ty
Stat 252
October 31st, 2017
Confidence & Prediction Intervals
Now that we know how to make an inference about the slope parameter, 1, lets now look at making
predictions for the values of the response
Stat 252
October 27th, 2017
HW 6: ANOVA
1. A safety analyst wants to compare how well people drive on three types of roads: paved, gravel,
and dirt. To measure driving performance, the analyst records
Stat 252
October 19th, 2017
ANOVA
ANOVA stands for _
ANOVA is a hypothesis testing procedure used to evaluate _ between
_ (populations).
Ex: Which Drug is Best for Providing Migraine Relief?
A drug co
Stat 252
October 17th, 2017
Chi-Square Tests of Homogeneity & Independence
The Chi-Square Goodness of Fit test is a way of determining whether a set of categorical data came
from a claimed distributio
Stat 252
October 6th, 2017
HW 4: Two Sample Means
Previously, both my 252 sections took three tests: math, verbal, and memory. I wanted to
study the effect of giving a countdown for each of the short
Stat 252
October 20th, 2017
HW 4: Chi Square
How good do you think you are at rock-paper-scissors? You are going to play rock-paper-scissors against
the computer. Go to http:/www.nytimes.com/interacti
Stat 252
October 3rd, 2017
Paired t test: Dependent Samples
A paired t-test is used to compare two population means where you have two samples in which:
Examples
Before-after observations on the same
Stat 252
September 15th, 2017
JMP HW 1 (Due Wednesday, September 20th)
Attached to PolyLearn is the dataset for rollercoasters around the world. There are two different
files that are the same dataset
Stat 252
October 30th, 2017
Inference for Regression
Recall: Least Squares Regression
^y = b0 + b1x, where b0 is the intercept coefficient and b1 is the slope coefficient
o
Slope coefficient estimated
Stat 252
October 2nd, 2017
Two Sample t-test for Means
Prior, we used a one sample t-test to test whether the population mean of a variable was equal to a
specific value.
Now, what if we were interest
Stat 252
September 25th, 2017
One Sample Mean Hypothesis Test
Central Limit Theorem for Sample Means
Suppose that the population distribution of a quantitative variable (X) has mean and standard
devia
Stat 252
September 21st, 2017
Confidence Interval for Population Proportion
We will now learn how to estimate the unknown value of a population proportion based on the result of
a sample proportion.
1
Gabe Zachrich
HW 2
1)
a. The variable is whether or not a student ate breakfast that morning (yes or no) and it is
categorical
b. The relative parameter in the study is the proportion of Americans bet
Stat 252
October 6th, 2017
Review Sheet for Exam 1
Confidence Intervals
o General Ideas
Form: point estimate(statistic) + (critical value) x (standard error)
Interpretations: of confidence interval
Stat 252
September 18th, 2017
Sampling Distribution of a Sample Proportion
Review:
A variable is a characteristic of a person or thing that can be assigned a number or a category.
This person or thing
Stat 252
September 19th, 2017
One Sample Proportions Hypothesis Test
Hypothesis test: Assesses the plausibility of a particular claim about the parameter.
Null Hypothesis (H0): = The claim being teste
Stat 252
September 22nd, 2017
HW 2
1. Breakfast is the most important meal of the deal. However, millions of Americans skip breakfast
every day. The most common reasons cited for missing breakfast are
Gabe Zachrich
HW 3
1. a) Cal Poly students
b) hours per week spent working out, quantitative
c) the parameter of interest is the population average, or mu (), of Cal Poly students for how
long much th
Stat 252
November 6th, 2017
Review Sheet for Exam 2
Chi-Square Tests
o Goodness-of-Fit
Specified/claimed distribution of one categorical variable
o Two-way tables
Test of Homogeneity vs. Test of Ind
Gabe Zachrich
Stat 252
September 15th, 2017
JMP HW 1 (Due Wednesday, September 20th)
a)
There are a total of 76 coasters with more than twice the number of steel roller coasters than wooden
roller coa
Stat 252
October 31st, 2017
Standard Error of Slope Coefficient
Using previous notes, rewrite the formula for the standard error of the slope coefficient.
SE(b1) =
Using words, explain what each symbo
Statistics
Descriptive Statistics
Inferential Statistics
Is a science of
collecting, analyzing,
presenting, and
interpreting data
Refers to methods
for summarizing and
organizing the
information in a
Stat 252
February 16, 2017
Inference for Regression
Recall: Least Squares Regression
^y = b0 + b1x, where b0 is the intercept coefficient and b1 is the slope coefficient
o
Slope coefficient estimated