Day Sun Mon Tue Wed Thu Fri Sat Births 89 114 76 109 75 74 1

Solution

Births really are not evenly distributed across the days of the week. Here are data on 658 births in the same locale.

Day

Sun.

Mon.

Tue.

Wed.

Thu.

Fri.

Sat.

Births

89

114

76

109

75

74

121

Table value of chi square at 0.05 level =12.592

Calculated chi square 26.2 > 12.592 table value

The null hypothesis is rejected

Births are not equally probable on all days of the week.

There is no evidence against equal rates of birth for all days of the week.    

Goodness of Fit Test

observed

expected

O - E

(O - E)