# CourseErrors Found in 2021 Study Materials P1.T2. Quantitative Methods

#### Nicole Seaman

##### Director of FRM Operations
Staff member
Subscriber
Please use this new thread to let David and I know about any errors, missing/broken links, etc. that you find in the 2021 materials that are published in the study planner under P1.T2. Quantitative Methods. This will keep our forum much more organized. We appreciate your cooperation!

PLEASE NOTE: Our Practice Question sets already have links to their specific forum threads where you can post about any errors that you find. This thread is for any other materials (notes, spreadsheets, videos, etc.) where you might find errors.

Information needed for us to correct errors:

• Reading
• Page number
• Error

#### reiss1

##### New Member
Subscriber
Hello,

On Ch2 notes p. 14, i believe the central moments are 2nd, 3rd, 4th, instead of 1st, 2nd 3rd, as highlighted in orange.

Thanks,
Reiss

#### reiss1

##### New Member
Subscriber
Hello,

On Ch2 notes p. 10, i believe the "<=" highlighted orange should be "<".

Thanks,
Reiss

#### reiss1

##### New Member
Subscriber
Hello,

On Ch3 notes p. 8, I believe Var(Y) is "a^2* σ^2".

Thanks,
Reiss

#### dla00

##### New Member
Subscriber
Hello,

Regarding Chapter 1: Fundamentals of Probability, Study Notes.

On page 27 answer 300.1.C, the last term should be +0.75*6 or () before 6^2/16.

#### dla00

##### New Member
Subscriber
Hello,

Regarding Study Notes: Random Variables (Chapter 2).

A couple of questions:

1. On page 10, why do we have two f(x) for Bernoulli's pmf?
2. Just below the above, when defining CDF of Bernoulli, I think F(x)=1-p when 0 <= x < 1, e.g the last inequality should be strict (notes say x <= 1).

Thanks!

#### David Harper CFA FRM

##### David Harper CFA FRM
Staff member
Subscriber
Hi @dla00
1. Not sure why we have the second one: it's almost certainly that we retained a legacy expression from the prior reading. Although I don't like the second one, now that I look at it. You can see by the text that it's trying to operationalize the statement "The pmf is the difference of the CDFs evaluated at consecutive values in support of X" but I don't see the point of that in a Bernoulli. In a binomial it could be useful; i.e., binomial P(X = 5) = P(X ≤ 5) - P(X ≤ 4).
2. Yes, I agree, as does wikipedia https://en.wikipedia.org/wiki/Bernoulli_distribution . Tagged for fix. Thank you!

#### Garbanzo

##### Member
Subscriber

P1.T2 Chapter 2 Random Variables, Study notes page 7:

should say:

"The cumulative DISTRIBUTION function (CDF) associates with either a pmf or PDF (i.e., the CDF can apply to either a continuous or DISCRETE random variable)."

P1.T2 Chapter 2 Random Variables, Study notes page 15:
last sentence should read:

"the pmf refers to a discrete distribution, while the pdf refers to a continuous distribution"

P1.T2 Chapter 2 Random Variables, Study notes page 15:

Pr(X less than or equal to q)

#### Garbanzo

##### Member
Subscriber

P1.T2 Chapter 3 Common Univariate Random Variables, Study notes page 16:
should be excess kurtosis

P1.T2 Chapter 3 Common Univariate Random Variables, Study notes page 7:
lambda*t should be in brackets

cross-reference with wikipedia

#### Attachments

• 1634552107500.png
235 bytes · Views: 0

#### Garbanzo

##### Member
Subscriber

P1.T2 Chapter 5 Sample moments, Study notes page 23:
should be sample 'covariance' instead of variance

#### Garbanzo

##### Member
Subscriber

P1.T2 Chapter 6 Hypothesis testing, Study notes page 27:
should read "outside" n standard deviations, not "within"

#### Garbanzo

##### Member
Subscriber

P1.T2 Chapter 7 Linear regression, Study notes page 4:
This should be the other way around. The Y is a function of X.

Replies
10
Views
674
Replies
8
Views
542
Replies
18
Views
893
Replies
11
Views
1K
Replies
6
Views
503