Question

In a control study the relationship between chlorinated swimming pool water and enamel erosion on teeth was investigated. A total of 249 individuals were included in the study. Depending on whether you swam 6 hours or more (group 1) compared to less than 6 hours per week (group 2), the outcome was as follows: Group 1: 150 individuals, of which 32 had enamel erosion. Group 2: 144 individuals, of which 17 had enamel erosion. Use appropriate statistical test to analyze if there is a significant relationship between enamel erosions on teeth and number of hours in swimming pool per week. State test, test value and p-value.

Answer 1

Sol:

Ho:There is no relationship  between enamel erosions on teeth and number of hours in swimming pool per week.

Ha: There is a relationship between enamel erosions on teeth and number of hours in swimming pool per week.

alpha=0.05

chi sq test statistic is calculated as

=sum(O-E)^2/E

degrees of freedom=(r-1)(c-1)

=(2-1)(2-1)

=1

p value in excel

==CHISQ.DIST.RT(4.802,1)

=0.028426719

p<0.05

Reject Ho

Accept Ha

Conclusion:

there is a significant relationship between enamel erosions on teeth and number of hours in swimming pool per week.

State test

Ho:There is no relationship  between enamel erosions on teeth and number of hours in swimming pool per week.

Ha: There is a relationship between enamel erosions on teeth and number of hours in swimming pool per week.

test value

CHI SQ=4.802

and p-value=0.028426719