Enjoy learning Statistics Online! Please be sure to share and subscribe to our YouTube channel.

ASK THE PROFESSOR FORUM

Course Documents

Chapter 1 - Intro

Chapter 2 - Methods for Describing Sets of Data

Chapter 3 - Probability

Chapter 4 - Discrete Random Variables

Chapter 5 - Normal Random Variables

Chapter 6 - Sampling Distributions

Chapter 7 - Confidence Intervals

Chapter 8 - Tests of Hypothesis: One Sample

Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples

Sample Exam I: Chapters 1 & 2

Sample Exam II: Chapters 3 & 4

Sample Exam III: Chapters 5 & 6

Sample Exam IV: Chapters 7 & 8

Ask the Professor Forum

When you are calculating the class width. How do you decide when to round to 2 or more decimal places? This question comes from Chapter 2 homework question 12. Thanks for your time.

Posted to STATS 1 on Saturday, January 18, 2014   Replies: 1


Professor Mcguckian
01/19/2014
2:53 AM EST

Hi Azariel,

When determining class width follow this simple guideline. If the class width calculation gives you a decimal round to the nearest whole number. If the class width turns out to be a whole number, try using the next highest whole number. 

Usually, the value will need to be higher than the calculation of width = range/# of classes. Remember that formula only provides the smallest width that might work. It typically does not work. The only way to know for sure is to try to form your classes with the value to see if the last class contains your largest data value. If it does, you have an acceptable width (note: there is more than one correct answer for these problems).

See the video below for more detail,

Professor McGuckian

Post a reply / comment below or click here to submit a new question to the forum.