用卡方检验检查hr数据集中2个变量之间的关系？
tbl = table(my_dataset$JobSatisfaction, my_dataset$MaritalStatus)
chisq.test(tbl)
# Error in chisq.test(tbl) : at least one entry of 'x' must be positive
summary(my_dataset$JobSatisfaction)
# Low Medium High v. High NA's
# 0 0 0 0 600
summary(my_dataset$MaritalStatus)
# Divorced Married Single
# 139 261 200