求大神帮助!Hypothesis Test two sample test question

求大神帮助!Hypothesis Test two sample test question
题目如下：
The agency has always valued houses higher if they are primarily made of brick. In fact
they usually add on an extra $15000 to the valuation if it is a brick house.
Separate the data into two groups. Group 1: Brick houses; Group 2: Non-brick houses.
i.Fully investigate the hypothesis that brick houses sell for more money on
average than non-brick houses. State all required assumptions, indicate your
chosen level of significance (and why you chose it) and give a plain-English
conclusion.
ii.Test the agency’s hypothesis that $15000 should be added to the valuation of
brick houses. Does the sales data support that?
想问一下两个问题Ho和H1的式子分别要怎么列? 先谢过了!