Sean Bowers
Lab4
Part 1.
3.
a. Regression Line Fit: Y(stiffness) = -25434 + 3885
X(density)
b. R Squared Value: 79.7%
5.
Scatterplot of sreis1 vs X(density)
4
3
sreis1
2
2
1
0
0
-1
-2
-2
5
10
15
X(density)
20
25
8. The only suspected outlier I saw when us

Chapter 2: Looking at Data-Relationships
2.1 Relationships
- What is an association between variables? [knowledge of one variable tells you about
the values of another variable]
- Explanatory and response variables
- Key characteristics of a data set
Asso

CH 5 SAMPLING DISTRIBUTIONS
5.1 THE SAMPLING DISTRIBUTIONS OF A SAMPLE MEAN
- Population vs sampling distribution
- The mean and std of the sample mean
- Sampling distribution of a sample mean
- Central limit theorem
Parameters and statistics
- A paramete

Chapter 3
Producing Data
3.1 sources of data
3.2 design of experiments
3.3 sampling design
3.4 toward statistical inference
3.5 ethics
3.1 Sources of Data
- Anecdotal data
- Available data
- Sample surveys and experiments
- observation vs experiment
Obtai

7.1 Inference for the Mean of a Population
- The t distributions
- One-sample t confidence interval
- One-sample t test
- Matched pairs t procedures
- Robustness of the t procedures
The t Distributions
When the sampling distribution of xbar is close to No

Chapter 4
Probability: The Study of Randomness
4.1 Randomness
4.2 Probability Models
4.3 Random Variables
4.4 Means and Variances of Rnadom Variables
4.5 General Probability Rules
The Language of Probability
Chance behavior is unpredictable in the short r

Mean = average
Median = middle, or mean of most 2 middle
Mean and median are symmetric if close
The quartiles Q1 and Q3 - observations in increasing order, locate median.
Q1 is the median of the observations whose position in the ordered list is to
the le

Problem 71
Gender
Female
Male
n
60
132
X(Juvenile)
48
52
a) Find the proportion of juvenile references for females and its standard error. Do the
same for males.
Female: 48/60 or .8 is the proportion. SE =
.8(1.8)
60
Male: 52/132 or .3939 is the proporti

Problem 1
Increased Time?
Female
Male
Total
No
245
212
457
Yes
47
21
68
Total
292
233
525
a) Find the conditional distribution of increased Facebook time for females.
No: 245/292 = .84
Yes: 47/292 = .16
b) Do the same for males.
No: 212/233 = .91
Yes: 21/

Problem 7
The average annual amount the n = 1601 families paid for college tuition was $20,902. The
standard deviation was $7500.
Would the margin of error for a 95% confidence interval be roughly doubled or halved if the
sample size was raised to n = 640

Problem 8
A researcher conducted the study by recording the behaviors of 2049 children in grades 4 to 6
in 33 schools in the lunchroom. One of the conclusions of the study was that girls discarded
more food than boys.
Is this an observational study or exp

Problem 27
Scatterplot of Calories vs PercentAlcohol
350
300
Calories
250
200
150
100
50
2
4
6
8
10
12
PercentAlcohol
Results exclude specified rows: 104
There appears to be a fairly strong positive correlation between the calories and percentage of
alcoh

6.1 Estimating with Confidence
6.2 Tests of Significance
6.3 Use and Abuse of Tests
6.4 Power and Inference as Decision
Statistcal Inference
- STatistical inference provides methods for drawing conclusions about a ppoulation
fomr aopdaot
Simple Conditions