Answer :
Answer:
95% Confidence interval: (5.5,8.5)
Step-by-step explanation:
We are given the following data in the question:
8,10,8,4,5,7,3,10,8
Sample size,n = 9
Population standard deviation = 2.3
Formula:
[tex]Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}[/tex]
[tex]Mean =\displaystyle\frac{63}{9} = 7[/tex]
Sample mean = 7
95% Confidence interval:
[tex]\mu \pm z_{critical}\dfrac{\sigma}{\sqrt{n}}[/tex]
Putting the values, we get,
[tex]z_{critical}\text{ at}~\alpha_{0.05} = 1.96[/tex]
[tex]7 \pm 1.96(\dfrac{2.3}{\sqrt{9}} ) =7 \pm 1.5 = (5.5,8.5)[/tex]
is the required confidence interval for population mean.