STA 210 - Homework 11 Section IV. B. and Lab 11 Section IV. B. Questions 1) What is the z used to create a 95% confidence interval? 2) What is the level of significance for a 95% confidence interval? A random sample of 45 Hollywood movies had a mean length of 111.7 minutes. Suppose the population standard deviation is 13.8 minutes. Use this information to answer questions 3-4. 3) Construct a 99% confidence interval for the population mean length of Hollywood movies. 4) Interpret the 99% confidence interval created in question 3. A sociologist sampled 200 people who work in computer related jobs and found that 42 of them have changed jobs in the past year. Use this information to answer questions 5-6. 5) Construct a 99% confidence interval for the percentage of people who work in computer related jobs and have changed jobs in the past year. 6) Interpret the 99% confidence interval created in question 5. An internet service provider sampled 540 customers, and found that 75 of them experienced an interruption in high-speed service during the previous month. Use this information to answer questions 7-10. 7) Find a point estimate (sample proportion) for the population proportion of all customers who experienced an interruption. 8) Construct a 95% confidence interval for the population proportion of all customers who experienced an interruption