Age in Years 0 Safety Seat1143 1328 1086 3557 No Restraint 270 249 368 887 1454
ID: 3322156 • Letter: A
Question
Age in Years 0 Safety Seat1143 1328 1086 3557 No Restraint 270 249 368 887 1454 1670 1626 4750 The table gives the by age and the type of restraint used. A Chi-square test was run and the value statistic was 6.4808 number of infants involved in automobile accidents over a 5 year period categorized of the appropriate test (a) What is the appropriate reference distribution? C Sguae distab (b) What exactly were the null and alternative hypotheses being testd? HDThere is no difference ininjunes? duse to type of veshaint ,a-There is a difference in # of inunes due to type of vestr (c) Under the null hypothesis, How many one year olds would be expected among the infants involved in auto accidents who used no restraints?Explanation / Answer
a) Here we are trying to test the relationship between two variables therefore this is a chi square distribution. The degrees of freedom here are computed as:
DF = (num of column - 1)*(num of rows - 1) = 2*2 = 4
Therefore this is a chi square distribution with 4 degrees of freedom
b) As we are trying to test here whether there is a relation between the age and the type of restraint used, therefore the null and the alternate hypothesis here would be given as:
H0: The age and the type of restraint used are independent variables
H1: The age and the type of restraint used are associated and are not independent variables
c) The expected frequency here is computed as:
Ei = (Row Sum * Column Sum ) / Total
Ei = (887*1670) / 4750 = 311.8505