Old Final: Stat3093 August 1996


                                                                    
name ___________________________________________________________         
HAND IN THIS PAGE         THE MARKER NEEDS THE VERSION NUMBER 11         
                                                                         
QUESTION ONE                                                             
   0   1 1                                                               
   1   5          This stem and leaf diagram                             
   2   2 4 9      is made from data consisting                           
   3   3          of one or two digit integers.                          
   4   1 2                                                               
   5              Calculate the quantities                               
   6   4 8        requested below:                                       
                                                                         
FIRST, SECOND & THIRD QUARTILES _______ _______ _______                  
                                                                         
MEAN (AVERAGE)                           ______________                  
                                                                         
STANDARD DEVIATION                       ______________                  
                                                                         
QUESTION TWO                                                             
Classify these plots as suitable or unsuitable for regression            
 A                    B                     C         *   *              
 |         *          |* *                  |   *  *                     
 |       *            |     * *             | *   *    * * *             
 |     *              |         *           |  * *  *   *                
 |   *                |          *   *      |  *   *                     
 | *              *   |                     | *                          
 +------------------  +------------------   +----------------            
                                                                         
 D *   *              E             *   *   F              *             
 |     *              |          *          |        *                   
 |       * *          |        *       *    |    *                       
 |         *          |      *   *      *   |  *                         
 |                    |     * *  *  *       | *                          
 |                *   |   **  *             |*                           
 +------------------  | * *                 +----------------            
                      +-------------------                               
                                                                         
QUESTION THREE                                                           
Given independent random variables, X, Y, with                           
           E{X} = 111,   E{Y} =  63                                      
           V{X} =  12,   V{Y} =  40                                      
Evaluate the expectation and standard deviation of                       
              3 ( 3X/4 + 4Y/5 ) / 5                                      
                                                                         
QUESTION FOUR                                                            
It is said that more moss grows on the north sides of of trees.          
Assume  60 trees are classified as North, South, East, or West           
according to which side shows the most moss.  This is condensed          
to a summary of three catagories:                                        
                North    South  East+West    Total                       
                  17       19       24         60                        
                                                                         
 (a) State the appropriate null hypothesis.                              
 (b) Perform an appropriate hypothesis test.                             
 (c) The chi_square table value for testing at alpha = 5% ___________    
 (d) Is the null hypothesis rejected at 5%?               YES__  NO__    
 (e) State a conclusion in terms of the original                         
     problem, i.e. the moss, in one or two sentences                     

William Knight / Math Dept / University of New Brunswick knight@unb.ca