Stat 20 Fall 2014 Finals Review PDF and CDF
Probability Density Function (PDF)
In pdfs, the area under the graph represents probabilities. For a pdf, the total area under the graph is 1. Why?
Continuous random variable X has PDF f(x) if
February 10, 2014
Please write your name below and circle your section.
Answer the questions in the space provided. There are questions on the back.
This quiz covers material from Homeworks 1 a
1. Suppose you draw 10 tickets from a box with 20 red tickets and 30 blue tickets.
(a) How many draws result in exactly 4 red tickets, if you draw without replacement?
(b) Repeat part a, but with the draws done with replacement.
2. Three cards ar
Instructor: Tessa Childers-Day
11 March 2014
Please write your name and student ID below, and circle your section. With your
signature, you certify that you have not observed poor or dishonest conduct on the part of
your classmates. Y
GSI and Section #:
Show your work for all the problems. Good luck!
1. We surveyed 100 men about their weights and heights, and got the following results:
average height = 69 inches,
average weight = 170 pounds,
Statistics 20: Midterm Solutions Summer Session 2007 1. [20 points] Pressure and Boiling Points. (a) [5 points] What is the equation of the regression line for predicting P RES from T EMP ? Solution: Here the x variable is TEMP in Fahrenheit and the y var
Statistics 20: Quiz 4 Solutions
1. A team of doctors want to estimate the life expectancy of students afflicted with the rare genetic disease statinotisticitis; however, only 15 known cases have ever been diagnosed. The sample reported a mean lifespa
Statistics 20: Summer Session 2007 Quiz n. 1 Friday July 6, 2007
Full Name (Please print):
YOU MUST SHOW WORK TO RECEIVE ANY CREDIT
1. The British government conducts regular surveys of household spending. The average weekly household spending on
Notation and Denitions
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 probabil
STAT 20 - Fall 2011 - Practice Midterm 1
Most explanations require just a sentence or two. On calculations, show your
work and work through to a numerical answers, upto at least 2 decimal places.
1. Below are the statistics of 3 lists of numbers. The aver
1. I record daily high temperatures in Berkeley for 90 days. The average of the rst 30 days is 70
degrees Fahrenheit with an SD of 8 degrees. In the next 60 days, the average is 60 degrees with an
SD of 6 degrees.
(a) What is the average te
Section Plan 3/6
1. FPP Problems: Ch16, Set A, #4-5
2. Suppose a fundraising game is being held, where thousands of tickets (>5000) are sold.
Each ticket costs $5, and the purchaser of the ticket wins a prize depending on what is
printed on the tic
# to simulate uniformly distributed data, we can use the function sample()
n <- 10000
die <- sample(1:6, size = n, replace = TRUE)
#calculate the mean
#proportion of sixes, compare to 1/6
mean(die = 6)
#calculate the probability of throwing mo
Stat 20 Section
Feb 16, 2012
1. From Tuesdays section: plotting and regression in R
The Crime dataset is at: http:/rss.acs.unt.edu/Rdoc/library/Ecdat/html/Crime.html
google data sets for Econometrics
# vector to represent the biased coin
coin <- c(rep(1,8), rep(0,2)
# generate a sample of 15 flips
n <- 15
my.flips <- sample(coin, size = n, replace = TRUE)
# calculate the sample statistics
prop.head <- mean(my.flips)
se <- sd(my.flips) / sqrt(n)
Thursday, March 22, 2012
A friend of mine has an unfair coin. He ipped the coin 15 times and observed 13 heads and 2
Now, Im wondering how biased this coin is. In other words, what proportion of times will this
coin ip a head?
Stat 20 Section Plan
Feb 14, 2012
1. R System Good-to-Knows:
- remember:getwd(),setwd(C:/Boriska/Stat20/) (Windows example)
common mistake: dont try to use tilde ~ in Windows to begin the file path
- make sure youre in the right directory!
- list files in
# Tuesday, March 6
# Part (a)
# Out of ten tickets, possible net gains would like
net.gain <- c(20, rep(5,2), rep(-5,7)
# To make the 'big box', just repeat this vector 500 to represent all 5000
box.model <- rep(net.gain, 500)
# Part (c)
Next lets write down Markovs Inequality using random variables and expectation