The owner of a store wants to examine whether method of payment (with either cash, credit card or debit card) and age group (of either 18 years, between 18 to 40 years, and 40 years) of paying customers, are independent. The following table summarises the observed frequencies:

	Method of payment
Age	Cash	Credit card	Debit card	Total
18 years	24	23	2	49
between 18 to 40 years	27	19	23	69
40 years	6	12	2	20
Total	57	54	27	138

What is the critical value if testing at of 5%?

Please give your answer correctly rounded to two decimal places.