A survey of 47 randomly selected iPhone owners showed that the purchase price has a mean of $660 with a sample
standard deviation of $25. (Use t Distribution Table. https://ezto-cf-media.mheducation.com/Media/Connect_Production/bne/Lind_9e/chapter_09/students_t_dist_table.jpg)
1. Compute the standard error of the sample mean. (Round your answer to 2 decimal places.)
2. Compute the 95% confidence interval for the mean. (Round your answers to 3 decimal places.
Confidence interval is between _____ and _____
3. To be 95% confident, how large a sample is needed to estimate the population mean within $8? (Round up your answer to the next whole number.)