STA 201 Written Assignment 7

Write your responses to the following topic.

Outliers: We know many types of data fall into a normal distribution with most of the observations falling

toward the middle. However, sometimes data are outliers or data that are very different – larger or smaller

– from the rest of the members of the sample. Think of an example in the real world of an outlier and

discuss its effect.

STA 201 Written Assignment 8

The written assignment draws on case study discussion exercises at the end of chapter. When preparing

your assignment, please identify each answer clearly by question and its number.

Case Study: Chest Sizes of Scottish Militiamen (p.295): Answer a,b,c,d. You must calculate results by

hand (though you may use any technology of your choice to verify your answers).

a.) Construct a relative-frequency histogram for the chest circumference data, using classes based on a

single value.

b.) The population mean and population standard deviation of the chest circumferences are 30.85 and

2.07, respectively. Identify the normal curve that should be used for the chest circumference.

c.) Use the table on page 254 to find the percentage of militiamen in the survey with chest circumferences

between 36 and 41 inches, inclusive.

Note: As the circumferences were rounded to the nearest inch, you are actually finding the percentage of

militiamen in the survey with chest circumference between 35.5 and 41.5 inches.

d.) Use the normal curve you identified in part (b) to obtain an approximation to the percentage of

militiamen in the survey with chest circumference between 35.5 and 41.5 inches. Compare you answer to

the exact percentage found in part (c).

STA 201 Written Assignment 9

Write your responses to the following topic.

Errors in testing: Think of one example of a Type I and Type II error in everyday life and comment on the

ramifications of those errors.

STA 201 Final Project