ECON
Stat3022HW2

# Stat3022HW2 - Homework 2 Stat 3022 February 5 2010 1.57 >...

• Notes
• 3

This preview shows pages 1–3. Sign up to view the full content.

Homework 2 Stat 3022 February 5, 2010 1.57 > hist(CRP) > boxplot(CRP) > summary(CRP) Min. 1st Qu. Median Mean 3rd Qu. Max. 0.000 0.000 5.085 10.030 9.420 73.200 Histogram of CRP CRP Frequency 0 20 40 60 80 0 5 10 15 20 25 30 0 20 40 60 We can see that there is a sharp right skey in the historgram from the plots. Mainly the histogram. 1.62 summary(over65) Min. 1st Qu. Median Mean 3rd Qu. Max. 5.70 11.70 12.75 12.54 13.48 17.60 The IQR=1.8. So 1.5*IQR=2.7. So Q1-2.7=9 and Q3+2.7=16.2. We can see that Alaska and Florida are outliers along with Utah. Problem 1.80 Group ¯ X s 1 23.75 5.06 2 14.08 4.98 3 15.77 5.76 1

This preview has intentionally blurred sections. Sign up to view the full version.

group1 group2 5 10 15 20 25 30 5 10 15 20 Histogram of group1 group1 Frequency 15 20 25 30 35 0 1 2 3 4 Histogram of group2 group2 Frequency 0 5 10 15 20 0 1 2 3 4 5 Histogram of group3 group3 Frequency 0 5 10 15 20 25 0.0 1.0 2.0 3.0 The histograms show that logging seems to reduce the number of trees per plot and that recovey is slow. The box plot shows that there are no extreme
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: outliers. Problem 1.111 A)The mean is C, and the meadian is B ( the right skew pulls the mean to the right). B) Mean A, median A C) Mean A, median B (the left skew pulls the mean to the right). 1.114 The middle 95% fall within two standard deviations of the mean or between 234 and 298 days. The shortest 2.5% of all pregnancies are shorter than 234 days. 1.122 25% of of the observations fall below -.6745 (qnorm(.25)) 35% of the ob-servations fall above .3853 (qnorm(.65)). 1.140 A) The quartiles for a standard normal dist are ± . 6745 (qnorm(.25),1norm(.75)) 2 B) X . 25 = μ + σ * -. 6745 and X . 75 = μ + σ * . 6745 C) X . 25 = 255 . 2 and X . 75 = 276 . 8 3...
View Full Document

• Fall '08
• Staff

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern