A marketing researcher wants to estimate the mean amount spent per year ($) on a web site by membership member shoppers. Suppose a random sample of 150 membership member shoppers who recently made a purchase on the web site yielded a mean amount spent of $55 and a standard deviation of $52. Complete parts (a) and (b) below. a. Is there evidence that the population mean amount spent per year on the web site by membership member shoppers is different from $52? (Use a 0.10 level of significance.) State the null and alternative hypotheses. Ho: H H1: u (Type integers or decimals. Do not round. Do not include the $ symbol in your answer.)

I get the solving part but what I don't understand is how is goes from a number to sudenly becoming 0. What's being plugged in? For example from (3+2/x-1/x^2)/(4+3/x-1/x^2) suddenly becomes, (3+0-0)/(4+0-0) = 3/4

Are you 100% sure about the answer?Also, can you rewrite it in neat handwriting please!