<< Chapter < Page Chapter >> Page >
Practice exercise for Descriptive Statistics

Student learning outcomes

  • The student will calculate measures of the center of the data.
  • The student will calculate the spread of the data.

Given

The population parameters below describe the full-time equivalent number of students (FTES) each year at Lake Tahoe Community College from 1976-77 through 2004-2005. ( Source: Graphically Speaking by Bill King, LTCC Institutional Research, December 2005 ).

Use these values to answer the following questions:

  • μ = 1000 FTES
  • Median = 1014 FTES
  • σ = 474 FTES
  • First quartile = 528.5 FTES
  • Third quartile = 1447.5 FTES
  • n = 29 years

Calculate the values

A sample of 11 years is taken. About how many are expected to have a FTES of 1014 or above? Explain how you determined your answer.

6

Got questions? Get instant answers now!

75% of all years have a FTES:

  • At or below:
  • At or above:

  • 1447.5
  • 528.5
Got questions? Get instant answers now!

The population standard deviation =

474 FTES

Got questions? Get instant answers now!

What percent of the FTES were from 528.5 to 1447.5? How do you know?

50%

Got questions? Get instant answers now!

What is the IQR ? What does the IQR represent?

919

Got questions? Get instant answers now!

How many standard deviations away from the mean is the median?

0.03

Got questions? Get instant answers now!

Additional Information: The population FTES for 2005-2006 through 2010-2011 was given in an updated report. (Source: http://www.ltcc.edu/data/ResourcePDF/LTCC_FactBook_2010-11.pdf). The data are reported here.

Year 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11
Total FTES 1585 1690 1735 1935 2021 1890

Calculate the mean, median, standard deviation, first quartile, the third quartile and the IQR. Round to one decimal place.

mean = 1809.3
median = 1812.5
standard deviation = 151.2
First quartile = 1690
Third quartile = 1935
IQR = 245

Got questions? Get instant answers now!

Construct a boxplot for the FTES for 2005-2006 through 2010-2011 and a boxplot for the FTES for 1976-1977 through 2004-2005.

Got questions? Get instant answers now!

Compare the IQR for the FTES for 1976-77 through 2004-2005 with the IQR for the FTES for 2005-2006 through 2010-2011. Why do you suppose the IQRs are so different?

Hint: Think about the number of years covered by each time period and what happened to higher education during those periods.

Got questions? Get instant answers now!

Questions & Answers

Explain the following terms . (1) Abiotic factors in an ecosystem
Nomai Reply
Abiotic factors are non living components of ecosystem.These include physical and chemical elements like temperature,light,water,soil,air quality and oxygen etc
Qasim
what is biology
daniel Reply
what is diffusion
Emmanuel Reply
passive process of transport of low-molecular weight material according to its concentration gradient
AI-Robot
what is production?
Catherine
Pathogens and diseases
how did the oxygen help a human being
Achol Reply
how did the nutrition help the plants
Achol Reply
Biology is a branch of Natural science which deals/About living Organism.
Ahmedin Reply
what is phylogeny
Odigie Reply
evolutionary history and relationship of an organism or group of organisms
AI-Robot
ok
Deng
what is biology
Hajah Reply
cell is the smallest unit of the humanity biologically
Abraham
what is biology
Victoria Reply
what is biology
Abraham
HOW CAN MAN ORGAN FUNCTION
Alfred Reply
the diagram of the digestive system
Assiatu Reply
allimentary cannel
Ogenrwot
How does twins formed
William Reply
They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
what is respiration
Deborah
what is genetics
Josephine Reply
Genetics is the study of heredity
Misack
how does twins formed?
Misack
What is manual
Hassan Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Collaborative statistics. OpenStax CNX. Jul 03, 2012 Download for free at http://cnx.org/content/col10522/1.40
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Collaborative statistics' conversation and receive update notifications?

Ask