I'm so confused and frustrated with this question, I've already asked this question here before twice and I still don't understand how they arrived at the final answer (see attached photo, it's from a different tutor). Firstly, how is it that there are 11 and 7 observations for that data set when there are clearly 20 on each side in the given problem? There are 20 values for untreated and 20 for treated. A total of 40 observations. Also, where is it said that it's subcompact and compact? I don't understand this. Please discuss this thoroughly.

Please help. I need the following:

(1) the null and alternative hypothesis

(2) the procedural steps in SPSS using an independent sample t-test so that I can perform it on my own. Please attach the SPSS output so that I have a reference for when I perform it in SPSS as well. (the previous tutor didn't give me the requested SPSS output, I think he/she used excel instead :

(3) interpret the SPSS result and discuss or interpret the statement:

"assuming the population variances from both conditions are equal, is there evidence of a difference in the mean surface hardness between untreated and treated steel plates? Use a=0.05"

(4) determine the p-value in (3) and interpret its meaning

Independent two sample t -test Hypothesis, Ho : There is no evidence of subcompact cameras have better battery life than compact cameras. H: There is evidence of subcompact cameras have better battery life than compact cameras. t-Test: Two-Sample Assuming Equal Variances Subcompact Compact Mean 207.2727 220 Variance 881.8182 3366.6667 Observations 11 7 Pooled Variance 1813.6364 Hypothesized Mean Difference 0 df 16 t Stat -0.6181 P(T