A Test of Writing Ability Is Given to a Random $\overline { \mathrm { d } }$

question 27

Multiple Choice

A test of writing ability is given to a random sample of students before and after they completed a formal writing course.The results are given below.Construct a 99% confidence interval for the mean difference between the before and after scores if $\overline { \mathrm { d } }$ (before - after) = 2.0 and sd =2.6457 $\text { Before } 70\quad80\quad92\quad99\quad93\quad97\quad76\quad63\quad68\quad71\quad74$ After 69 79 90 96 91 95 75 64 62 64 76

• A)(-0.2,4.2)
• B)(-0.1,4.1)
• C)(-13.6,17.6)
• D)(1.2,2.8)
• E)(-0.5,4.5)

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Definitions:

Railroad Tracks

Parallel steel rails on which trains run, forming the fundamental infrastructure for railway transportation.

New Jersey

A state located in the Northeastern and mid-Atlantic regions of the United States, known for its diverse population, industries, and being a pivotal site of revolutionary war battles.

Maryland

A U.S. state located in the Mid-Atlantic region, known for its significant historical landmarks, diverse geography, and as the birthplace of the national anthem.

Independent Employment

Independent employment describes a work arrangement where individuals are self-employed or work as contractors, having control over their working conditions and not being employed by an organization or company.