We use the t distribution to construct a confidence interval for the population
ID: 3182901 • Letter: W
Question
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find t2,df for the following scenarios. Use Table 2. (Round your answers to 3 decimal places.) t/2,df a. A 90% confidence level and a sample of 25 observations. b. A 95% confidence level and a sample of 25 observations. c. A 90% confidence level and a sample of 19 observations. d. A 95% confidence level and a sample of 19 observations.
Explanation / Answer
Using standard t-table, we have below values computed
Sr. # alpha alpha/2 Sample size df Notation Value1 Value2 1 0.1 0.05 25 24 t(0.05,24) 1.711 -1.711 2 0.5 0.25 25 24 t(0.025,24) 2.064 -2.064 3 0.1 0.05 19 18 t(0.05,18) 1.734 -1.734 4 0.5 0.25 19 18 t(0.025,18) 2.101 -2.101