please help me wih this Confidence Interval and Sample Size Determination

1. A random sample of 49 shoppers showed that they spend an average of $23.45 per visit at the Bookstore. The standard deviation of the population is $2.80. Find the 90% confidence interval of the true mean.2. A researcher wishes to estimate within $25 the average amount spent on vacation of the content creators in one year. If she wish to be 90% confident, how large of a sample will be necessary if the population standard deviation is $80.3. The lengths (in minutes) of a random selection of movies in Netix are listed below. Estimate the true mean length of all the lms or movies in Netix. Assume the variable is normallj,r distributed. 93 33 T6 92 T? 31 T3 100 T3 T6 4. A survey found that out of a random sample of 200 students, 168 said they were interrupted three or more times an hour by phone messages, fb notification, etc. Find the 90% confidence interval of the population proportion of students who are interrupted three or more times an hour.5. It was believed that 25% of the students have internet connection at home. How large a sample is necessary to estimate the true proportion of students with internet connection with 95% confidence and within 3% percentage points.6. Use the data from number 3 to estimate the population variance and standard deviation of the length of films or movies in Netflix. Assume the variable is normally distributed