Question

1. Table below shows a relationship between the temperature and number of traffic accidents in small town for a sample of 7 different days.  [4+2+4+2=12pts]

Temperature (in Celsius degrees )... x	32	13	24	20	10	4	36
# of traffic accidents  ...y	7	4	9	11	3	5	8

1. Find a correlation coefficient r, round it to 4 decimal places.

2. Describe the direction and strength of this association: …………………………

3. Find the equation of regression line.

4. Sketch it graphically, find/display values of both x- and y-intercepts.

Answer 1

SOLUTION- WE USE MINITAB-16 FOR CALCULATIONS

1.) TO COMPUTE CORRELATION COEFFICIENT:

STEPS- ENTER THE DATA> STAT> BASIC STATISTICS> CORRELATION> SELECT THE SAMPLES> OK.

THE PEARSON'S CORRELATION COEFFICIENT IS 0.173

2.) THE DIRECTION OF ASSOCIATION IS POSITIVE AND THE STRENGTH OF THE ASSOCIATION IS WEAK

3.) TO COMPUTE REGRESSION EQUATION:

STEPS- STAT> REGRESSION> REGRESSION> SELECT NO OF ACCIDENTS AS RESPONSE AND TEMPERATURE AS PREDICTOR> SELECT THE GRAPHS AS 4 IN 1> OK.

THE REGRESSION EQUATION IS, ACCIDENTS= 3.89 + 0.142*TEMPERATURE

4.) GRAPH-

****IN CASE OF DOUBT, COMMENT BELOW. ALSO LIKE THE SOLUTION, IF POSSIBLE.