# Stat 202: Lecture 14 (covers pp. 160-165)

Nathan VanHoudnos
10/27/2014

### Agenda

1. Midterm (test and quarter!) comments
2. PSA
3. Lecture 14 (covers pp. 160-165)

### Midterm distribution

mean(midterm)

[1] 63.5493

median(midterm)

[1] 64


### Midterm distribution

Percent of the class with a $$X$$ or above:

     [,1]
[1,] "A   11%"
[2,] "B   25%"
[3,] "C   41%"
[4,] "D   58%"


After dropping

• 3 lowest checkpoints
• 1 lowest homework
     [,1]
[1,] "A   23%"
[2,] "B   62%"
[3,] "C   89%"
[4,] "D   94%"


No “curve” is needed.

### Question Breakdown

Questions 4 and 5 differentiated the class.

• Homework 4 score had very little power to predict performance
• Time seemed to be an issue for some students
• Many students were simply wrong.

### Moving Forward

• To determine final exam length I will triple the time it took me instead of doubling it.

• You will see something like Q4 and Q5 on the final.

• The final Q4 and Q5 can replace the midterm Q4 and Q5 scores.

### Agenda

1. Midterm (test and quarter!) comments
2. PSA
3. Lecture 14 (covers pp. 160-165)

### PSA - Office hours

I need to cancel my office hours this week.

• If you need to meet with me, as always, feel free to send me an email.

• Aaron will still hold his office hours on Thursday.

• (For that matter send Aaron email if you can't make his either.)

### PSA - Intersex Awareness day

From Emily Quinn (Animator for Adventure Time):

Being intersex means that you were born with differences in your sexual characteristics — these differences can affect genes, chromosomes, genitalia, reproductive organs, hormones and also things like body hair and how much you sweat.

• Quinn's AMA on reddit (yesterday).

• Surprising Fact: Intersex is as common as being a natural redhead (1/20,000).

• For pedagogic reasons, Stat 202 gender is binary.

### Agenda

1. Midterm (test and quarter!) comments
2. PSA
3. Lecture 14 (covers pp. 160-165)

Assume that the height of adult men is normally distributed with a mean of 69 in. and a standard deviation of 2.8 in.

Assume that the height of adult men is normally distributed with a mean of 69 in. and a standard deviation of 2.8 in.

• Randomly select 15 men from the population and measure their heights:
67.2 69.5 66.7 73.5 69.9 66.7 70.4 71.1 70.6 68.1 73.2 70.1 67.3 62.8 72.1