# Chi Square

#### Boston111

##### New Member
2. A recent survey of 1,223 children, ranging in age between 8 and 12 years old, reported the following results. Suppose that the survey was based on 600 boys and 623 girls.

What Tweens did : Boys/ Girls
Played video game: 498/243
Read a book for fun 276/324
Shopped at a mall: 144/262

For each type of activity, determine whether there is a difference between boys and girls at the 0.05 level of significance.

Im really struggling with this one because the total people surveyed is 1,223, but when you add up these numbers you get 2114. I know how to do a chi square test in excel just these numbers are throwing me off. Please help if you can I will greatly appreciate it!

#### Mean Joe

##### TS Contributor
Make a chi-square table for each type of activity.
eg for the activity "played video games" make a 2x2 table

For each type of activity, determine whether there is a difference between boys and girls at the 0.05 level of significance.

#### Boston111

##### New Member
So to find an expected value for boys who played video games would it just be 498*741/1223? Because that would be the total who voted times the amount of boys who voted divided by the total number of people surveyed.

#### Karabiner

##### TS Contributor
So to find an expected value for boys who played video games would it just be 498*741/1223
The empirical value for a cell cannot be used to calculate the
expected value. You have to use the marginal distributions.
rate of boys * rate of video gamers * total sample size.

With kind regards

K.