Asample size of n=12 does not have a known population standard deviation. the population appears to be normally distributed. determine whether a margin of error should be calculated using a critical value of z a/2, a critical value of 1 a/2, or neither

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books