Let be the population mean strain in a way that conveys information about precision and reliability.
The sample mean is the best point estimate of the true population mean .
As per given , we have
Sample size : n= 12
degree of freedom :
Sample mean :
The true average strain in a way that conveys information about precision and reliability= 25.0
sample standard deviation : s= 3.3
Significance level :
Since sample population standard deviation is unknown , so we use t-test.
Critical t-value for t :
95% Confidence interval for true average strain in a way that conveys information about precision and reliability:
The 95% Confidence interval for true average strain in a way that conveys information about precision and reliability:
We 95% confident that the true population average strain in a way that conveys information about precision and reliability lies between 22.9 and 27.1 .