A unit rate means for one, so in this case they mean for one pound of the horse feed which brand sells the highest. You would divide the cost into the number of pounds for each brand. Now, compare all the brands and see which one is highest.
Have you used the length*width*height?
Complete Question
The complete question is shown on the first uploaded image
Answer:
The null hypothesis is 
The alternative hypothesis is 
Step-by-step explanation:
From the question we are told that
The number observations is 
The annual salary (in dollars) is y
The mean score on teaching evaluation is x
The the relationship between the y and x is

Where
is the mean of the equation so
The null hypothesis is 
The alternative hypothesis is 
Now you can see its pretty simple, its 128 but the way i got it is first you double 8 which makes 16 right then double 16 and you can see you got 32 then double 32 which makes 64 so next what you have to do is double 64 Obiously so you just double those numbers to get 128....Get it?