## Colorado State University — Pueblo, Spring 2017 Math 156, Introduction to Statistics Course Schedule and Homework Assignments

Here is a link back to the course syllabus/policy page.

This schedule is will be changing very frequently, please check it at least every class day, and before starting work on any assignment (in case the content of the assignment has changed).

Below, we refer to the class text Lies, Damned Lies, or Statistics as LDLoS. The whole book is available here, although below there will be links to particular sections of the book that you are asked to read and in which you will find problems to do.

If you see the symbol below, it means that class was videoed and you can get a link by e-mailing me. Note that if you know ahead of time that you will miss a class, you should tell me and I will be sure to video that day for you.

Homework for a particular day is due that day, either in class or handed in at my office by 3pm.

#### Week 1

• :
• :
• Read LDLoS up to and including §1.3.2
• Some content we discussed, terms defined:
• graphs for categorical variables:
• bar charts
• pie charts
• graphs for a quantitative variables:
• a stem-and-leaf plot
• the most important such graph: a histogram
• Hand in BI1. This will be an unusual one: write down two or three things you were surprised about in the organization of this course. Be specific, mention types or numbers or formats of some assignments, etc.
• :
• Some content we discussed, terms defined:
• histograms
• variants: frequency and relative frequency
• bins [or classes] and their edge behavior
• shape: symmetric, skew, multimodal
• Quiz 1 today (on material covered on Monday and Wednesday this week)
• Hand in HW1: problems 1.{1, 2, 3} on this page of LDLoS.
• Hand in BI2 (on an idea from Wednesday's class or readings)
• Today [Friday] is the last day to add classes.

#### Week 4

• :
• Some content we discussed, terms defined:
• going over Quiz 3
• going over HW3
• independent and dependent variables [also called explanatory and response variables]
• deterministic and non-deterministic relationships between variables
• scatterplots; their shape, strength, and direction
• Hand in BI9 (on an idea from Friday's class or readings)
• Hand in ASE3. See above, here and here, for the required parts of an ASE (the second of those explanations above also has a list of a few sites you could go to in order to find materials for an ASE, although of course something you are interested in yourself would probably be much more fun). Please look for something which mentions variability, standard deviation, quartiles, and/or outliers, or which uses the five-number summary or boxplots
• :
• Read LDLoS §2.2 and §2.3
• Some content we discussed, terms defined:
• qualitative description of the association shown in a scatterplot
• shape,
• strength, and
• direction
• the [Pearson] correlation coefficient $r$ of bivariate data
• defining formula
• computing with electronic tools
• always satisfies $-1\le r\le 1$
• meaning of the size of $|r|$
• meaning of the sign of $r$
• independence of units
• Hand in BI10 (on an idea from Monday's class or readings)
• :
• Some content we discussed, terms defined:
• the idea of linear regression
• sketching the line of best fit
• one point the regression line should go through: $(\overline{x},\overline{y})$.
• the residuals of a regression line
• the least squares regression line [LSRL]: definition
• formulæ for the LSRL
• Hand in BI11 (on an idea from Wednesday's class or readings)
• Quiz 4 today [on material from last Friday to this Wednesday]

#### Week 5

• :
• Read LDLoS Chapter 3 Intro & §3.1 & §3.2
• Some content we discussed, terms defined:
• going over Quiz 4
• going over HW4
• Review of equations of lines — particularly their slope and $y$-intercept
• Repeating (from Friday) the basic definitions and facts for the LSRL
• Simpson's Paradox (which is in our textbook LDLoS here)
• Applications of the LSRL:
• interpolation
• interpretation in a problem context of the slope and $y$-intercept of an LSLR
• Hand in BI12 (on an idea from Friday's class or readings)
• :
• Some content we discussed, terms defined:
• bivariate outliers
• sensitivity of the correlation coefficient and LSRL to outliers
• correlation is not causation
• extrapolation
• Review for Test I. See this review sheet.
• Hand in BI13 (on an idea from Monday's class or readings)
• Hand in HW5: problems 3.{1, 2, 3} on this page of LDLoS.
• :
• Test I in class today. Make sure you are comfortable with the material outlined on this review sheet. Don't forget your calculator, or other favorite electronic device, if you use one!

#### Week 6

• :
• Yes, we do have class today, even though it is the federal holiday commemorating the birthday of George Washington (who was actually born on February 22nd, 1732), although this holiday is often casually referred to as "Presidents' Day."
• Test I post-mortem.
• Hand in ASE4. Please try to find something which mentions or uses scatterplots, correlation or the correlation coefficient, or maybe even [linear] regression
• :
• Read LDLoS Introduction to Part 2, Introduction to Chapter 4, and §4.1
• Some content we discussed, terms defined:
• the idea of randomness
• sample spaces, outcomes, events
• the idea of probability, a probability model
• complement of a subset [event], notation $E^c$, translation into English: not
• probability rule for complements
• Hand in BI14. This is a special one: please write a paragraph about how you think Test I went for you. Are you perfectly content with how it turned out? If not, what do you think was the cause of the trouble? And what can you do next time to make things better?
• Hand in Test I revisions, if you like.
• :
• Some content we discussed, terms defined:
• intersection of sets [events], notation $A\cap B$, translation into English: and
• union of sets [events], notation $A\cup B$, translation into English: or
• disjoint events, notation $\emptyset$ for the empty set
• finishing the definition of a probability model
• Venn diagrams — how to fill in numbers correctly
• Hand in BI15 (on an idea from Wednesday's class or readings)
• Hand in HW6: problems 4.{1, 2, 3} on this page of LDLoS. [NOTE: due to network problems, this assignment was not posted until late Thursday afternoon. Therefore, if you hand it in on Monday, that will not be considered late!]

#### Week 7

• :
• Read LDLoS §§4.1 & 4.2
• Hand in HW6 [details above], if you did not do so on Friday
• Hand in BI16 (on an idea from Friday's class or readings)
• ASE5 is not due today -- in fact, no ASE is due this week; if you did one before seeing this notice, save it and use it in the future.
• Some content we discussed, terms defined:
• more on the ideas of sample spaces, events, and probability models
• finite probability models, such as [fair] coins and [fair] dice
• :
• Some content we discussed, terms defined:
• mutually exclusive is a synonym of disjoint
• the general rule for computing $P(A\cup B)$, whether or not the events $A$ and $B$ are disjoint
• starting conditional probability, including its formal definition, computing examples, etc.
• two events being independent
• Hand in BI17 (on an idea from Monday's class or readings)
• :
• Read LDLoS §4.2 & §4.3.1
• Some content we discussed, terms defined:
• more examples of turning statements in English into formulæ with events, and computing their probabilities.
• more discussion of the difference (they're completely different!) between disjoint and independent, and the different uses they have
• very start of the idea of a random variables [RVs]
• Hand in BI18 (on an idea from Wednesday's class or readings)
• Hand in HW7: problems 4.{4, 5, 6} starting on this page of LDLoS; if you want a little extra time, this could come in on Monday without any penalty
• Quiz 5 was handed out today — if you didn't pick up a copy in class, e-mail your instructor and you will get a PDF by return email.

#### Week 8

• :
• :
• Reread LDLoS §4.3.1, §4.3.2, & §4.3.3
• Some content we discussed, terms defined:
• mostly working through recent terms/ideas even more
• discussion of what makes an RV either discrete or continuous
• Hand in BI20 (on an idea from Monday's class or readings)
• :
• Read LDLoS §4.3.4 & §4.3.5
• Some content we discussed, terms defined:
• [probability] density functions for continuous RVs
• the uniform distribution on an interval $[x_{min},x_{max}]$
• the Normal distribution with mean $\mu$ and standard deviation $\sigma$
• the standard Normal distribution
• Hand in BI21 (on an idea from Wednesday's class or readings)
• Quiz 6 today [on material from last Friday to this Wednesday]
• No homework due today: it will instead be due on Monday

#### Week 9

• :
• Some content we discussed, terms defined:
• standardizing a non-standard Normal RV
• the 68-95-99.7 Rule for Normal RVs
• using electronic tools to compute Normal probabilities.
• Hand in BI22 (on an idea from Friday's class or readings)
• No ASE due today — in fact, none due this week. Although there will be one due after Spring Break, so if you think you will be unable to work at all over the break, it might make sense to start that ASE now — maybe just going as far as finding a source and, if you are worried about whether it will make a good ASE, asking your instructor.
• Hand in HW8: problems 4.{7, 8, 9, 10} starting on this page of LDLoS
• :
• Review for Test II. See this review sheet.
• Hand in HW9, which is just problem 4.11 on this page of LDLoS
• Hand in BI23 (on an idea from Monday's class or readings)
• :
• Test II in class today. Make sure you are comfortable with the material outlined on this review sheet. Don't forget your calculator, or other favorite electronic device, if you use one!
• Today [Friday] is the last day to withdraw (with a W) from classes.

#### Week 10

• Spring Break! No classes, of course.

#### Week 11

• :
• Test II post-mortem.
• Hand in ASE6. Please try to find something which mentions or uses Normal distributions [which is sometimes called a "bell[-shaped] curve"], uniformly distributed, or maybe even some article which talks about the uses of randomness or random numbers in modern science or computers ‐ e.g., sometimes this is called "using Monte Carlo methods." For this ASE only, and only if you talk about one of these last few topics, you may write a brief summary of something which is mostly an educational source, and which therefore does not have live data, variables, population, etc. Contact your instructor if you have any concerns about what you you intend to do.
• :
• Some content we discussed, terms defined:
• Hand in BI24. This is a special one: please write a paragraph about how you think Test II went for you. Are you perfectly content with how it turned out? If not, what do you think was the cause of the trouble? And what can you do next time to make things better? Do you think the ideas you talked about in BI14 for test improvement were effective -- were you actually able to use them?
• :
• Some content we discussed, terms defined:
• Hand in BI25 (on an idea from Wednesday's class or readings)
• Quiz 7 today
• Hand in HW9:

 Everything below this point is under construction.

#### Week 12

• :
• Read, if you like, SIS §8.3 — that is the book's description of the material we've already seen on this page. New material to read for today is SIS §8.4, or this page for our version of this.
• Some content we discussed, terms defined:
• Always start a hypothesis test by stating the population, RV, parameter of interest, and null and alternative hypotheses $H_0$ and $H_a$
• formulæ for the test statistic in a hypothesis for a population mean $\mu$ in the case of
• known population standard deviation $\sigma$: the test statistic is a $z$-statistic, with formula $z=\frac{\overline{X}-\mu_0}{\sigma/\sqrt{n}}$; you compute the $p$-value with the standard Normal table (based upon what kind of alternative hypothesis you have); this whole test is then called a "$Z$-Test".
• unknown population standard deviation: the test statistic is a $t$-statistic, with formula $t=\frac{\overline{X}-\mu_0}{s/\sqrt{n}}$, where $s$ is the sample standard deviation; you compute the $p$-value with the appropriate part of a table of Student's $t$-Distribution depending upon the degrees of freedom $df=n-1$ and in the direction determined by the kind of alternative hypothesis you have); this whole test is then called a "$T$-Test".
• Hand in BI28 (on an idea from Friday's class or readings)
• Hand in ASE9. Try to find one about a confidence interval for a population proportion -- there should be tons of these in coverage of the presidential election. It can help to look (again) for the phrase "margin of error." Be careful not to get a source which is about a confidence interval for a population mean; proportions will often be expressed as percentages, remember.
• :
• Read SIS §8.5 or our version of this material
• Some content we discussed, terms defined:
• the test statistic for a hypothesis test of the population proportion: $z=\frac{\widehat{p}-p_0}{\sqrt{p_0(1-p_0)/n}}$
• the process for a hypothesis tests for the population proportion, which is just like the $Z$-Test using this new version of the $z$-statistic
• Hand in BI29 (on an idea from Monday's class or readings)
• :
• Review for Test II. See this review sheet.
• Hand in BI30 (on an idea from Wednesday's class or readings)
• Quiz 10 today [on confidence intervals for the population mean with known and/or unknown population standard deviation and/or for the population proportion; particular attention on the logic and structure of hypothesis test and the meanings of $p$-values]
• Hand in HW10: In these problems, always use the $p$-value approach of the descriptions in the web pages for our class: one, two, three, and four. Problems to do are SIS §8.2: 8, 14; SIS §8.4: 12, 18; and SIS §8.5: 12, 14.

#### Week 14

• :
• Skim SIS §10.3 and read SIS §10.4
• Some content we discussed, terms defined:
• review of equations of lines:
• slope
• $y$-intercept
• equation: $y=mx+b$
• the idea of the least squares regression line [LSRL]
• how to compute the LSRL
• electronic tools to compute correlation coefficients and LSRLs:
• Hand in BI32 (on an idea from Friday's class or readings)
• Hand in ASE10: this is a "free-range" ASE: pick a topic that interests you, a nice article or webpage or whatever, which has a clear bit of statistical content, and write up an ASE as we've been doing all semester. [So be sure to clearly talk about the population, variable[s], parameter[s], sample, methods, etc.] If you want to do one which has a scatterplot and/or mentions correlation, that would be great [but is not required, since we've just started talking about this material].
• :
• Some content we discussed, terms defined:
• using the LSRL to guess missing values of a linear relationship [interpolation]
• potential issues with the LSRL:
• correlation is not causation — but it sure is a hint
• sensitivity to outliers — but what are outliers on scatterplots?
• extrapolation — but sometimes it's the best you can do
• the meaning of $r^2$, the square of the correlation coefficient
• time permitting, discussion of using LSRLs when the relationship is not linear
• Hand in BI33 (on an idea from Monday's class or readings)
• Hand in HW11: SIS §10.1: 4, 8, 12; SIS §10.2: 6, 12; and SIS §10.4: 4, 12.
• :
• Some content we discussed, terms defined:
• Hand in BI34 (on an idea from Wednesday's class or readings)
• No quiz today because this material [on scatterplots, the correlation coefficient, and least squares regression lines] will be tested in the [fairly short] midterm following our Thanksgiving Break.

#### Week 15

• :
• :
• Test III in class today. Make sure you are comfortable with the material outlined on this review sheet. Don't forget your calculator, or other favorite electronic device!
• Today is the last day to hand in any late work for credit, even with Homework Late Passes.
Please also hand in any unused Homework Late Passes you have left, for course extra credit.
• :
• Test III post-mortem will be sent by email! If you do not get an email with links to videos explaining how to do the Test III problems, inquire further (by email) about it. But there will be no in-person class.
• Make sure you drop by GCB314 at some point to pick up any graded work for which you may be waiting.
• Review for final exam by looking over this review sheet and watching this video.
• Hand in BI35, a special one: what do you intend to do for the next few days to enable you to do the best you possibly can on the final exam for this class? Be specific!