SHORT ANSWER WRITING ASSIGNMENT 19) In order to conduct inferential statistics the sample must be representative of the population. For lab purposes, we will assume that our sample of students is representative of the student body at BCTC. Is this the case? Explain. 20) Look at the 50% confidence interval for the population proportion of students who were born in Kentucky. a. Identify the interval. b. Explain why a 50% interval would not be of much use in estimating the population proportion. 21) Give the following confidence intervals for the population proportion of students who were born in Kentucky. a. 90% confidence interval b. 95% confidence interval c. 99% confidence interval d. What happens to the interval as the confidence level increases? Explain. 22) Look at the 95% confidence intervals for the population proportion of males/females who choose math as their favorite subject. a. Identify the interval for males. b. Interpret the interval for males. c. Identify the interval for females. d. Interpret the interval for females. 23) Look at the 95% confidence interval for the population mean of the variable Temp. a. Identify the interval. b. Interpret the interval. 24) Look at the 95% confidence intervals for the population means of the variable Sleep grouped by Gender. a. Identify the interval for males. b. Interpret the interval for males. c. Identify the interval for females. d. Interpret the interval for females.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
