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Thursday, May 23, 2013

Probability for Risk Management 2nd edition



I had no prior probability experience before using this book to pass exam p on my first try. The author does an excellent job of explaining the concepts in layman's terms. It is the most readable math text I've ever used. Supplement with SOA 153 and some practice exams and you will be ready for exam p.

The book get four stars because it's not perfect. Few things are.

My opinions seem to be shared by most of the other reviewers.
I also used the book to study for exam p. I have taken calculus one and two in college but never probability. This is a great book for learning the basics on your own. It seems to be written specicfically fo exam p.
It took me about a month and a half to get through the book. (chapters 1-11) I certainly will not be only relying on this book to pass the test.

It is very easy to read and not that thick, and the example problems within the chapter are easy very easy to understand. The questions at the end of the chapter aren't that difficult either. The last set of questions in the problem sets of every chapter are just taken from the soa 153. And here is where my major complaint lies. The difference between the logic used for solving the example problems and the logic used for solving the actuarial practice problems is rather a large jump. The book prepares you well enough, but the chapters could have used and walked you through a few trickier problems to get you used to the logic.
I had to look up a few of the answers occasionally. The material is covered in the book, only stated very differently for the test problems.

But in any case, this should not be your only study material. As I said, I did not know probability, and now i am on my way to passing the exam. With the two months remaining till I take the test, study guides, maybe reading through a more advanced probability book, and about four tons of practice tests and problem sets will see me through.

Overall, I am very, very happy with my choice on this book.

Edit: November 29th, Passed xam P on my first attempt. Everything is the same as I said before, but, And this is important, one or many other study guides and practice tests will be needed. This book is only a starting point for those who have not had probability.

Side note, the answer booklet is probably unneccesary, as most of the answers to the problems in the book can be found online for free. Then again, I suppose it wouldn't hurt.

This book is a recommended text for the SOA Exam P but it alone is not sufficient enough to practice for the exam. You can use this to understand the theory before moving on to a harder book such as the First Course in Probability, A (8th Edition) by Sheldon Ross. Exercises are too easy when compared with the real actuarial exam problems but may help to get the basic theory down. Overall, it is a good book to get started with.

I purchased this book (from a third party seller, Roy Mak) late last month to help prepare for the P1 exam. It arrived in less than four business days and was in excellent condition. It is very well-written and easy to read (quite an accomplishment for a book that deals with probability). Highly recommended!

I just got this book last week, I had previously decided to find a cheaper statistics/probability book that was cheaper but I finally came to my senses and just got something that was recommended for the Actuary Exam. I am not that far into the book but I am seriously loving it. It's so easy to read, it doesn't feel at all like a text book! If you don't have strong statistics and probability background this is the book you need. The authors go things at a level that is really easy to understand! Loving this book!

If you're looking at this book, presumably you're looking to study for the first actuarial exam P/1. I took the exam in February and scored a 9. I used this book, as well as the Sam Broverman Actex study guide and an Actex online course. This may have been overkill, but I was changing careers and wanted to be sure I'd have the resources to pass. Anyway.

While I wish there were 1 study guide or textbook that covered all the bases for all people, I'm skeptical that such a guide really exists. When deciding how to prep for exam P/1, students should consider how much they already know of the material. If you have a pretty decent statistics/probability background, a study guide from Actex or ASM might be better. If you need a more thorough discussion of basic probability & the motivation behind certain concepts, a textbook may be better. Personally, I think it's worth consulting at least 2 sources anyway just because different authors will have different styles and points of emphasis.

I like this book a lot, for what it is. It's among the most readable math books I've ever read. It uses very conversational language which makes it easy to follow, as other reviewers have pointed out. From what I've seen of Hassett & Stewart's Course 3 manual it has the same nice readable qualities. These guys do a nice job making the math accessible. They present each of the probability distributions and briefly describe the relative merits of each. There is intentionally very little theoretical discussion of the material, which may disappoint some readers, but there's no theory on the exam anyway, so the book seems to make a wise choice.

However, this book does have several shortcomings, and I believe you'll need additional resources to pass the first exam. The shortcomings are:

1) Some of the hardest problems on Exam 1 involve taking double integrals to solve for random variables with joint distributions or marginal distributions. If you've taken an advanced calculus course recently, you're probably fine with this stuff. I was somewhat rusty, and this book offers only a brief discussion of how to integrate these things. Really this is more of a calculus issue than a probability issue, but I wish the authors had spent more time on it since it can be confusing.

2) Generally, the exercises in this book in no way resemble actual SOA/CAS exam problems. It's nice to do some easy problems to make sure you understand the concepts, but you'll need to practice with a LOT of past exam problems to understand how you'll be expected to apply the material on the exam. You can of course get these for free from the SOA site, or buy a different study guide that has more exam problems.

3) The book doesn't cover more advanced & obscure topics that sometimes surface on exam 1. I had a problem on second-order statistics on the first exam that stumped me; I know Broverman had discussed it but this book had not. I don't think this is a huge drawback; probably there are only 1 or 2 questions on the exam that may not be explained by this book's content.

Again, just to sum up, this is a great text to prep for Exam 1 if:

-You want a nice, readable discussion to the material and you don't have a solid background already, specifically in the more advanced topics.

-You don't mind using another study guide or practice exams to get more experience with real exam problems.

And here are some reasons why you may want to avoid this book:

-You already have a decent grasp of probability & statistical distributions and are just looking for something to tell you what you need to know, without a lot of fuss or explanation. Buy a study guide instead. I didn't like the Broverman very much, but I'm sure some people do, and there are probably better guides out there too.

-You want to buy one book that will have everything you need to pass the exam. (As I said above, I'm skeptical about this approach, but I'm sure it's been done.)

Maybe I should have rated this book lower, but I think it does very well what it intends to do - the real question is whether you're among the intended audience or not.

The following review refers to the 1999 version specifically. Amazon chose to include it with future version(s).

This is not quite your normal review because it's also being used as a reference for something in case I want to refer back to it for something, but this reference does give you a detailed idea of why I say the things I do about the book.

Based on the writing of this book, ASU (Arizona State University) probably has a great actuary program (undergrad or grad I think.) The terms in this book are well defined. This book tried to talk to students like they are human. It's not to drab, and makes smart comments like "Don't bet on it." which are witty enough and not too corny! (thumbs up) For people learning, this book minimizes fuss, frustration, and confusion. This book avoids the confusion by not explicating "too much" and saying things most books expect you to "figure out" intuitively. Most typos in this book are small compared to other books you may tun in to.

When the author wrote this book, in wasn't just "plugging in numbers," but you can tell that they "felt" the readers and a maximization for understanding too.

Sometimes the book likes to show an example, then present a formula. I like the way the book doesn't lead an example into a formula, because it can be more confusing and make the reader think that they should alrady know something. The book mentions alternate notational standards rather than letting the reader run into any potential problems on 2nd guessing.

One good note to add is that the dot in midair in some of the problems presented is multiplication and NOT the dot prodcut. This is a small, but possibly helpful tip the book should have mentioned.

I do not like the setup of formulas for exponential distribution. I always seem to be a "recipricol off" if I follow this book. Not that the way this book has the formulas is incorrect, but rather it's one of the few qualms I have with this book notationally.

If you would consider getting more than 1 book if you have time, if you want to just pass an actuarial exam, or interested in more but don't have time, you should strongly considering buying this book first. The way many examples were written are well thought out for understanding material rather than tricking you and making you think more or too much.

For people who have a great grasp on the material and little patience, this book may not be for you. You cannot deny the rarity of a book as well written as one such as this one for an introduction to statistics. Some people say the book is not for them, but just because the book is not for them does not mean that others should not consider using this book too. With over-the-top writing, all first Stat classes should use this book.

The following notes are based on the first 11 chapters out of the 12.

p. 32-33, Ex. 2.36- Excellent example of a trick permutation

p. 69 Bayes Theorem- top notch explanation

p. 78- discrete and continuous didn't mean anything different to me until this book came a long

p. 84- geometric sequence formula should use r^n instead of r^n-1. R^n-1 is thinking that the first term is 0 instead of 1, which is more confusing in this context. It's so confusing that I have to keep using this review as a reference to remember sometimes that it's the zeroeth term the book starts with and not the 1st term. r^n is definitely the mathematical standard, and does not need to be changed for any potential copyright issues.

p. 85 Fantastic explanation of how to round when given a problem. ROunding down could have been mentioned too, but wasn't so as not to confuse someone who doesn't think of the particular concepts intuitively.

p. 88 Great way to look at "expected" value- book explains how this term can be misleading in a few brief, concise setences.

p. 96-7 Perfect explanation for introducing the z-distribution (normal distribution).

p. 115 I actually understand hypergeometric distribution becase of this page. So, now instead of memorizing the formula, I feel I could just come up with it!

p. 117 I wish other books would mention "the finite population correction factor" the way this book does!

p. 118- "policyholder" easier to understand than the book's term "insured." It's hard not to like this book so far without being picky like this.

p. 125-26 Some stat book don't treat geometric distribution differently than binomial It's probably good to treat it separately since the expected values and variance have shortcuts

p. 130 Even with the negative binomial distribution, the book shows you how to think, not just receiving an entree on a platter without understanding the preparation. (Complicated proofs alone don't easily help readers- they can be be discouraging too.)
Also, the way the formula is devised for negative binomial makes it easier to understand and recognize than some other textbooks.

p. 155 should say great than or EQUAL TO to match up with [.50,1), a very small typo.

p.181 A reference to section 6.1.4, p. 144, would more strongly support the proof for V(aX + b) = a^2 V(x). Other than that, it is pretty well written. This proof is hard to follow and understand every detail at first, but author couldn't have written it better. Without being your tutor in person, lol, online should never fully replace a real live teacher/tutor- especially if they are good.

p.191 Important typo missed. Should be integration from 0 to infinity of e^(-ax) = a(e^(-ax))/(-a), NOT -e^(-ax)/(-a) This is the first major typo that was noticed. It confused me for awhile, but it can happen easily considering time constraints on publishing books, especially when working at a university.

p. 192 fractional factorials (n * pi^n) mentioned and though that was intereesting since I don't think about that usually

p. 195 Would be nice if integration by parts written out because of format of book (formulas and writing things out have been excellently elaborated on up to this point pretty much)

p. 199 Another big typo- should be e^(-lambda*b)-e^(-lambda*a)

p. 203- It would be helpful to note that Ex. 8.7 under Ex. 8.14 uses alpha = 1 is implied.

p. 222-230 I feel book is not clear enough on distributions. Feel like forumlas are being thrown at me. Maybe because of the complexity of the true nature to understand these, the formulas cannot be elaborated on.

p. 231 Maybe "goodness of fit" should be mentioned before all the distributions?

p. 258 Impressive example of avoiding a common probability distribution trap. Even this book can get to be tedious because of the difficulty conceptualizing the most advanced topics, Chap. 8 and up.

p. 259 Great exaggeration for the term "point mass;" if this book had more color, it'd be more expensive, but the graphs coul be easily enhanced more, especially for a book well written as detailed oriented for a beginner like this one.

p. 274 nice quick review tip

p. 280 You may be introduced to a new way of representing repeating digits. In this case, a dot above the repeating digits. In this case, a dot above the repeating number(s) is used rather than the more ambiguous 3 dots (an ellipsis) or a line above the repeating pattern.

p. 301 Ex. 11.7 Needs a reference to Ex. 10.13 in addition

p. 306 -(mew_Y)*X-(mew_X)*Y could have been elaborated on the proof more

p. 310 11.2.6 (5) Missed an ending parentheses. NOT vital, but it confused me for a second.

p. 311, middle of page. If should be "it." small typo.

p. 322 "1 or more" rather than "1" claim specifically would make the problem seem more realistic.

After-thoughts: It would be nice to know that the mean for the exponential distribution is equal to the greek letter "mew" even though this can be assumed for any type of expected value. Not obvious on first sight.

p. 222 Ex. 8.28 (a) and (b): The step after F(6) and F(4) should be written out. The step shown is (3/4)^2.5 - (3/6)^2.5 at and first glance, you'd expect the 3/6 quantity to come first because of the "6" when "1 - (3/6)quan. - (1 - (3/4)quan.)" should be written out for clarity and to fit style of book.

p. 194 It should be noted that lambda in Ex. 8.8 is equal to 1/100, because lambda is not just given to you as the book makes it seem. Otherwise, exponential density distribution turns out to be poorly explained. If you look in a Wackerly Stat book, it will say 1/beta instead of lambda. What is really needed is both of these scenarios to be written out because you may have to deal with either one, and that took me awhile to figure out.

p. 115 k goes from max(0, n+r-N)
If you can't start from the zeroth term, you want to start from another term. This notation in the footnote is confusing without that explanation. Even for min(r,N) it would be nice to read that the minimum point has to be at r, but that it can never ever be lower than N.

Median should be defined as the observation in the middle (or the average of the two middle observations) for discrete samples or the 50th percentile for continuous samples rather than just "simply" 50th percentile.

For more advanced topics, or for learning advanced material, this book can get confusing because the notation doesn't always match up with details you need to know or understand outright. It's a great book to understand statistics in general, but now I see it could use quite a bit of improvement. Good book to get, but I'd get this book with another one if you're studying for the actuarial exam. Another thing to note is that the acturial exam has changed its format recently, so some of the material in here may not be as relevant, but it will be great for general math practice in some other applications you may run into if that is what you're looking for.

Product Details :
Hardcover
Publisher: ACTEX Publications; 2 edition (2009)
Language: English
ISBN-10: 156698548X
ISBN-13: 978-1566985482
Product Dimensions: 8.9 x 5.9 x 1.2 inches

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