Solutions to Final Exam Review Chap 21, 23, 26 and Midterm 1 material:
Midterm 1 material:
Problem 3. Central Limit Theorem (CLT) , draw from highly non normal box:
For each of the following, indicate the distribu
Elizabeth Wu
May 3rd, 2015
Review Sheet : Chapter 27 and 28
Chapter 27: More Tests for Averages
1. The Standard Error for a Difference
The standard error for the difference of two independent quantities is:
where,
a = SE for the first quantity
b = SE fo
Assignment #2
Pg. 23 (the refused group is your control here since they aren't examined)
10a) This is not a good comparison because the rates are very close 1.1 and 1.5 is not a big
change. It is biased for screening because the number for examined (scree
Assignment #3
Pg. 24
13) False, there is a confounding variable with the amount of students that applied to the
different departments. There was a different number of people that applied to departments A and
B.
Pg. 26
7)
a. Observational study
b. Educatio
Assignment #4
Pg. 27
12) As far as studying the voting behavior in the entire city as a whole, the people who registered
to vote may not vote for the same party. They may have registered as a specific party but voted
for a different candidate. An individu
Assignment #11
Pg. 167 #2 Answers: a) 79%, b) 38%, c)50%, d) 50%
Pg. 174 #2
No the tutoring had an effect on the final scores. The regression effect causes the numbers to be closer to the
average.
Pg. 176 #4
next problem Continued.
Pg. 178 #9 Answers: a)
1
Chapter 27: Two sample Tests
Recall the process of how to conduct two sample tests: (hypothesis testing)
1. Find the null and alternative hypothesis
a. Null- difference due to chance variation
b. Alt- difference not due to chance variation
2. Test Stati
Assignment #12
Pg. 187 #3 Person B will have a smaller rms error. (1-r^2)= [1-(0.6)^2]= 0.8. It will be
smaller by 0.8.
Pg. 198 #3 Answers: a) 38% (in the first picture), b) 59% (in the second picture)
#1 page 198
The rms error of reg line for predicting
1
Assignment #5
Pg. 65
5) The average age for registered students at universities in the U.S. would be larger.
Pg. 75
7)
a. Male average: 66kg=145.2lb
Male SD: 9kg= 19.8lb
Female average: 55kg= 121lb
Female SD: 9kg=19.8lb
b. 68%
c. Bigger than 9kg because
Stat 2 - Practice Test
1) In a study of blood pressure and number of children, it turns out that there is a strong positive correlation
between blood pressure and how many children they have. True or False:
a. People with high blood pressure tend to have
Stat 2 - Homework 2
Name: _ SID: _ GSI: _
1) True or False
a. A histogram allows you to visualize how values are distributed. True
b. Bars in a histogram can be rearranged. False
c. The area of the bars in a histogram represent the frequency of values in
1
Assignment #6
Pg. 74
3)
a. Without doing arithmetic, the average is around 5.
b. Without doing arithmetic, the SD is around 3.
Pg. 93 (pictured)
1) a. 20 scores
b. 21 scores
1)
Pg. 94
2
3) Pictured below: answers are a) 6.68% and b) 0.62%
Pg. 95
3
7) An
Assignment #13
Pg. 268
16) This is a statistic because they are making are saying similarly, the great kings
typically had prime ministers who were not as great. They are comparing it to the first
sentence, which is a fact.
Pg. 268, #17, Answer: 19.76%
Pg
1
Assignment #8
Pg. 124
6)
a. The average midterm score was around 75
b. The SD of the midterm scores was around 10.
c. The SD of the final scores was around 20.
d. The final exam was harder.
e. More spread in the final score
f. True
Pg. 128
1)
a. The cor
Assignment #9
Pg. 134- work shown below in picture #1b) Answer: r= 0.82
1b)
Pg. 143- work shown below in picture #4) Answer: Change of scales does not affect r. It stays the
same.
4)
Pg. 144
9) The bigger correlation will come from the weatherman who comp
Assignment #10
Pg. 146
2) For all the children together, the correlation would be somewhat more than 0.67. The initial
correlation separated each age from 6 to 11 so with all the data put together there will be a
stronger correlation, making it look more
Assignment #7
Pg. 104
1) False, there is always room for human error. It is impossible for human beings to perform
tasks without making an error. Humans are inherently made to make mistakes and learn
from them. The second measurement may be slightly diffe
Chapter 17-19 Review
Chapter 17
Expected Value for sum = number of draws
x
average of box
The sum of draws from a box is a random variable with a normal distribution. Its center is called
the expectation of the sum and the spread (SD) is called the standa
Midterm Review Sheet Ch. 8-12
Chapter 8:
Association:
With strong association between 2 variables, it helps when trying to predict the other.
With weak association- not much help.
Independent variable- this variable influences the dependent variable (x)
Midterm #1 Practice Questions
Chapter 1,2:
Q5) No, you cannot assume that one vet is better than the other. The case or severity of the
injury the raccoons have experienced may be different. Some raccoons may have had more
life-threatening injuries than o
Hank Ibser Statistics 2
. _ Study Guide For_the Midterm
The midterm Will cover the Follow1ng chapters with certain arts omitted:
Ch 1-2: Ideas in these chapters and terminology will be inc uded as
it relates to Ch 12, baSically section 1 oF each chapter.
Hank Ibser Statistics 2 Final Study Guide
See bspace for updates on office hours and instructions. The final
exam will be held on Tuesday Dec 15 from B-llam, in RSF Field House.
Please get to the final a little early as we will seat people by GSI.
The fin
Probability
Stat 2
Hank Ibser
Notation and Definitions
A = an event which may or may not occur (A)
Ac = the complement, or opposite, of event A (A complement)
P (A) = the probability that event A occurs (probability of A)
P (B|A) = the conditional probabi
1. Collecting data: experiments and observational studies
a. Randomization
b. Treatment and control groups
c. Blind/Double-blind
d. Confounding
e. Biases
2. Descriptive statistics
a. Histograms
b. Averages
c. SDs (RMS deviations)
d. Medians
e. Properties
1. Solutions same as for other version.
2. The chart below is adapted from a figure in the San Francisco Chronicle, May 18, 1992. It shows the
distribution of income for American families. Ranges include the left end point but not the right, as
usual. Wit
SOLUTIONS
1. The National Social Life, Health and Aging Project (NSHAP), is an in-home study of social relationships
and health in a large, nationally representative sample of men and women ages 57 to 85.
The first set of surveys was conducted in 2005-200