15 5 points We will be formulating a 95% confidence interval for / and want our margin of error to be not greater than 0.2. A trial sample has suggested that a reasonable estimate for o is 1.2. Which of the following statements about our full sample size is most appropriate? O Approximately 35 observations will ultimately be needed O Approximately 25 observations will ultimately be needed O Approximately 97 observations will ultimately be needed O Approximately 139 observations will ultimately be needed Approximately 231 observations will ultimately be needed None of the above is correct Next