Posted by Daniel on Thursday, March 7, 2013 at 10:10am.
A quiz consists of 10 questions. Each question is marked either “right” or “wrong.” For each student in the class, the instructor keeps a record of the number of right answers the student got. In the class, the average number of right answers is 6.2 and the SD of the number of right answers is 1.4.
(1) Find the average number of wrong answers.
(2) Find the SD of the number of wrong answers.

Statistics  PsyDAG, Thursday, March 7, 2013 at 11:01am
1. 10  6.2 = ?
2. 1.4

Statistics  Anonymous, Monday, March 11, 2013 at 5:49pm
1.3.8
2.1.4

Statistics  Gary, Tuesday, March 12, 2013 at 1:23am
"number wrong" = 10  "number right" is a linear transformation that says, "Multiply the list by 1, then add 10." The addition does nothing to the SD, and the multiplication by 1 multiplies the SD by 1=1. So there's no change to the SD. In terms of the histogram, the histogram for "number wrong" is a flip of the histogram for "number right," so the SD stays the same.
Answer This Question
Related Questions
 Statistics  In the quiz in Exercises 1 and 2, the grading scheme is as follows...
 STAT1  In the quiz in Exercises 1 and 2, the grading scheme is as follows: each...
 Statistics  A quiz consists of 10 multiple choice questions. Each question is ...
 statistic  A statistics quiz consists of 10 multiple questions. There are four ...
 statistics  In a particular class, there are 3 freshmen, 5 sophomores, 11 ...
 LBCC  A multiple choice quiz consists of 20 questions, each with 3 possible ...
 statistics  a quiz consists of 30 true or false questions. if the student ...
 stat probability  A multiple choice quiz consists of 20 questions, each with 3 ...
 English  There are 7 classes for first year students. Each class is composed of...
 statistics  A student is taking a multiple choice test where each question have...
More Related Questions