# Calculating the critical value

A sample of 500 drivers was asked whether or not they speed while driving. The following table gives a two-way classification:

We wish to test whether gender and speeding are related at the 1% significant level.

What is the critical value for the test? Also state the null and alternative hypothesis. I need help in this.

the critical value can be looked up in the $\chi^2$-table. The number of degress of freedem is $df=(r-1)\cdot (c-1)$

r=number of rows

c=number of columns

And here is $\chi^2_{\alpha}=\chi^2_{0,01}$

The null hypothesis is: There is no connectedness between the "gender" and "speedness"

The alernative hypothesis is: There is a connectedness between the "gender" and "speedness"

If the empirical $\chi^2$-value is equal or greater than $\chi^2_{0,01}$ we have to reject the null hypothesis-at the significance Level of 1%.

greetings,

calculus

• The critical value from table comes out to be 6.6349. Is that correct? – Hani Abdullah Apr 24 '14 at 17:41
• Yes. My table has only 2 digits after the point: 6.63 – callculus Apr 24 '14 at 21:15