Stat 231 Exam 2 Fall 2010
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1
10 pts
1. Below are 5 histograms and 5 normal plots. Each normal plot was in fact made from one of the data sets that pro
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STAT 231 EXAM 2
Name:
Two notes: rst, if a condence/signicance level is not provided, assume = 0.05. Second,
I will provide you with 3 quantiles in any question where you will need them. Choose the
correct one for the situation.
n
2 i=1 Xi
iid
1. If Xi Ex
STAT 231 EXAM 1
Name:
1. Prove that P(A ) = 1 P(A). (5 pts)
2. A machine produces earbud covers (iPod headphones), and the diameters of these covers are normally
distributed with mean 10.3mm and standard deviation 0.35mm.
a) An earbud is judged to be defe
STAT 231 EXAM1
Name:
1. What is a random variable? Give a denition or at least do your best to explain.
2. For any random variables X and Y , show that Var(aX + bY ) = a2 Var(X ) + b2 Var(Y ) + 2abCov(X, Y ).
3. A team of scientists has set out to answer
Stat 231 Homework Assignments/Fall 2011
HW1/ Due 8/25/11 1. Do Devore Chapter 1 Problem 42. (It's possible to use algebra to prove the relationships you are supposed to find here, but it will be sufficient for this exercise to use the numbers 2,3,3, 4,5 a
Stat 231 Homework Assignments/Fall 2010
HW1/ Due 8/26/10 1. Do Devore Chapter 1 Problem 42. 2. Do Devore Chapter 1 Problem 51 "by hand." That is, do the arithmetic required to compute the sample variance and sample standard deviation. Check your computati
Stat 231 Exam 2 Fall 2011
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1. Thicknesses of n = 6 sheets of wallboard before and after drying during manufacture, corresponding differences, and so
Stat 231 Exam 2 Fall 2011
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1. Thicknesses of n 6 sheets of wallboard before and after drying during manufacture, corresponding differences, and some
Stat 231 Exam 2 Spring 2010
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10 pts
1. US 5 cent pieces have weights that are roughly normal with mean 5.00 g and standard deviation .06 g . What is
Stat 231 Exam 2 Spring 2010
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10 pts
1. US 5 cent pieces have weights that are roughly normal with mean 5.00 g and standard deviation .06 g . What is
Stat 231 Exam 3 Fall 2010
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This exam concerns the analysis of some data of Prof. I-Cheng Yeh on compressive strength of concrete specimens of differ
Stat 231 Exam 3 Fall 2010
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This exam concerns the analysis of some data of Prof. I-Cheng Yeh on compressive strength of concrete specimens of differ
Stat 231 Exam 3 Fall 2011
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This exam concerns the analysis of some data collected by the Norwegian Public Roads Administration (part of the "NO2" da
Stat 231 Exam 3 Spring 2010
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This exam concerns analyses of some data collected by ISU students Flood and Shankwitz in a study of tempering (heat tr
Stat 231 Exam 3 Spring 2010
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This exam concerns analyses of some data collected by ISU students Flood and Shankwitz in a study of tempering (heat tr