Answer: ( 8.11 , 9.69)
the 95% confidence interval of the true mean weight
= ( 8.11 , 9.69)
Explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 8.9
Standard deviation r = 0.9
Number of samples n = 5
Confidence interval = 95%
z(at 95% confidence) = 1.96
Substituting the values we have;
8.9+/-1.96(0.9/√5)
8.9+/-1.96(0.4025)
8.9+/- 0.79
= ( 8.11 , 9.69)
Therefore at 95% confidence interval (a,b) = ( 8.11 , 9.69)