1)
90% confidence interval for proportion =0.797 ; 0.883
2)
95% CI for std deviation =17.273 to 38.385
Source: Time magazine, Oct. 2006. Work Interruptions Research by Steelcase found the average worker get interrupted...
10. Stock Prices A random sample of stock prices per share (in dollars) is shown. Find the 90% confidence interval for the variance and standard deviation for the prices. Assume the variable is normally distributed. Chapter 7 Confidence Intervals and Sample Size 404 3. Using Table G. find the values for en and icht a a0.05, n 12 b a 0.10,n-20 a0.05, n27 12.00 28.37 47.50 13.88 7.50 53.81 28.25 10.87 26.69 43.00 75.37 3.81 45.12 13.62 d a0.01,n=6 60.50...