Posted by Tyler on .
Suppose the following data are selected randomly from a population of normally distributed values.
42
51 43 48 41 57 54
39 45 48 45 39 46
Construct a 95% confidence interval to estimate the population mean.
Round the intermediate values to 2 decimal places. Round your answers to 2 decimal places, the tolerance is +/0.05.
I do not understand how to find the 's' for the estimate of standard deviation from the sample.
n=13
xbar=46
df= 12
alpha/2= 0.025
Therefore, t= 2.179
And I am stuck...

Stats 
Kuai,
n=13
xbar=46
df= 12
alpha/2= 0.025
Therefore, t= 2.179
Sd = 5.5377
t = 2.179
(42.65, 49.35)
Z = 1.96
(42.99,49.01)