Two Maths Problems

Two separate samples, each with n= 12 individuals, receives two different treatments. After treatment, the first sample has SS= 1740 and the second SS= 1560. 

a) find the pooled variance for the two samples. 
b) Compute the estimated standard error for the sample mean difference 
c) If the sample mean difference is 8 points, is this enough to reject the null hypothesis and conclude that there is significant difference for a two tailed test at the .05 level? 
d) If the sample mean difference is 12 points, is this enough to indicate a significant difference for a two tailed test at the .05 level? 
e)Calculate the percentage of variance accounted for (r^2) to measure the effect size for an 8-point mean difference and for a 12-point mean difference

2. Movie goers total sample is 458. 
148 x go to the day time viewing, 310 go to night time viewing.
calculate the 95% confidence interval for the proportion of movie goers who prefer the night time viewing - been going round and round in circles with this one.