Answer:
I 95%(μ)= [64.26; 85.74]
Step-by-step explanation:
The confidence interval formula is:
I (1-alpha) (μ)= mean+- [(t(n-1))* S/sqrt(n)]
alpha= is the proportion of the distribution tails that are outside the confidence interval. In this case, 5% because 100-95%
t(n-1)= is the critical value of the t distribution with 16-1 degrees of freedom for an area of alpha/2 (2.5%). In this case is 2.1314
We use the t-student distribution because the population standard deviation is unknown.
S= sample standard deviation. In this case 20.152
mean= 75
n= number of observations =16
The DATA file shows have 16 observations
Then, the confidence interval (95%):
I 95%(μ)= 75+- [2.1314*(20.152/sqrt(16))]
I 95%(μ)= 75+- [10.7379]
I 95%(μ)= [75-10.7379; 75-10.7379]
I 95%(μ)= [64.2620; 85.7379]
I 95%(μ)= [64.26; 85.74]