A marketing analyst sampled 121 college students and found that 42 of them preferred Spotify as their main music streaming service. a. Construct a 93% confidence interval for the proportion of all college students who prefer Spotify as their main music streaming service. Critical value: Z* = (Enter the positive one.) Margin of Error: E : Confidence Interval: b. Interpret your result in part (a) in a complete sentence. c. Based on the confidence interval, can the marketing analyst conclude that more than 30% of all college students prefer Spotify as their main music streaming service? Yes No d. Based on the confidence interval, can the marketing analyst conclude that more than 25% of all college students prefer Spotify as their main music streaming service? Yes No e. If 250 college students were sampled, would the width of the interval become wider or narrower? Wider Narrower f. If a 90% confidence level were used, would the width of the interval become wider or narrower? OWider